Explore topic-wise InterviewSolutions in Current Affairs.

This section includes 7 InterviewSolutions, each offering curated multiple-choice questions to sharpen your Current Affairs knowledge and support exam preparation. Choose a topic below to get started.

1.

Evaluate int (x + (1)/(x))^((3)/(2))((x^(2) -1)/(x^(2)) )dx

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ANSWER :`I = (2)/(5 ) (x + (1)/(x))^(5//2) + c `
2.

C_(1) + 4.C_(2) + 7.C_(3) +......+(3n - 2).C_(n) =

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`(3n - 4)2^(N + 1)`
`(3n - 4)2^(n - 1) + 2`
`(3n - 4).2^(n)`
`(3n - 4).2^(n - 1) + 1`

ANSWER :B
3.

Define binary operation on a set. Verify whether the operation * defined on Q set of rational number by a*b= ab+1 AA a,b in Q is commutative or assosiative.

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ANSWER :A BINARY operation * on a SET A is a function `* : Axx A to A.` As `ab+1 in Q` so * is binary
4.

The value of 50 sum_(r=1)^(49)(2r^(2) - 48r +1)/((50-r).""^(50)C_(r)) is "_____".

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SOLUTION :`underset(r=1)overset(49)sum(2r^(2)-48r+1)/((50-r)..^(50)C_(r))= underset(r=1)overset(49)sum((r+1)^2-r(50-r))/((50-r).^(50)C_(r))`
`= underset(r=1)overset(49)sum(((r+1^(2)))/((50-r)..^(50)C_(r))-(r)/(.^(50)C_(r)))`
`=underset(r=1)overset(49)sum((r+1)/((50-r)((.^(50)C_(r))/(r+1)))-(r)/(.^(50)C_(r)))`
`=underset(r=1)overset(49)sum((r+1)/(.^(50)C_(r+1))-(r)/(.^(50)C_(r)))`
`=(50)/(.^(50)C_(50))-(r)/(.^(50)C_(1))`
`= 50 - 1/50`
5.

On the set of positive rationals, a binary operation * is defined by a*b=(2ab)/5 . If 2 * x=3^(-1) then x=

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`2/5`
`1/6`
`125/48`
`5/12`

ANSWER :C
6.

Integrate the following functions : e^(x)(1+x)log(xe^(x))

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ANSWER :`XE^(X)[log|xe^(x)|-1]+C`
7.

In the parabola y^(2)-2y +8x -23 =0the length of double ordinate at a distance of 4 units from its vertex is

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2
8
12
` 8sqrt2`

ANSWER :D
8.

Prove that the area of the triagle only if z_1^2+z_2^2+z_3^2=3 z_0^2

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Solution :SINCE , `z_(1) , z_(2)` and origin form an EQUILATERAL triangle .
[`because ` if `z_(1) , z_(2) , z_(3)` from an equilateral triangle , then `z_(1)^(3) + z_(2)^(2) + z_(3)^(2) = z_(1) z_(2)+ z_(2)z_(3) + z_(3)z_(1)`]
`implies z_(1)^(2) + z_(2)^(2) + 0^(2) = z_(1)z_(2) + z_(2)*0 + 0*z_(1)`
`impliesz_(1)^(2) + z_(2)^(2) = z_(1)z_(2)`
`implies z_(1)^(2) + z_(2)^(2) - z_(1)z_(2) = 0`
9.

A :sin^(2) 5^(@) + sin^(2) 10^(@) + ..... + sin^(2) 85^(@) =17//2 R : If A+B=90^(@) , thensin^(2) A + sin^(2) B=1

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A is true , R is true and R is CORRECT explanation of A
A is true , R is trueand R is not correct explanation of A
A is true , R is false
A is false , R is true

ANSWER :A
10.

A cylinder is heated in such a way that its radius always remains twice of its height when the radius is 3 cm, find the rate of increase of its volume. The radius is increased at the rate of 2 cm/s. Also find the rate of increase of its total surface area.

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ANSWER :`27pi CM^(3)//s, 36pi cm^(2)//s`
11.

Evaluate int(1)/((x+1)sqrt(x+2))dx

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ANSWER :`LOG|(SQRT(x+1))/(sqrt(x+2)+1)|+C`
12.

State the converse, inverse and contrapositive ofprarr~~q propositions. Stating it as a conditional, wherever necessary.

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SOLUTION :`prarr~~q`
CON :`~~q rarrp`
INV : `~~prarrq`
CONT :`qrarr~~p`
13.

If vecE and vecF are complementary events of events E and F respectively and 0lt P(F) lt 1 , then :

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<P>`P(E//F)+P(vecE//F)=1 " or "P(E//vecF)+P(vecE//vecF)=1`
`P(E//F)+P(E//vecF)=1`
`P(vecE//F)+P(E//vecF)=1`
NONE of these

Answer :A
14.

If the arithmetic mean of the roots of quadratic equation is (8)/(5) and the arithmetic mean of theirreciprocals is (5)/(8) then the equation is

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`5X^(2)+16x+7=0`
`5x^(2)-16x+7=0`
`X^(2)-6x+7=0`
`5x^(2)+7x+16=0`

ANSWER :B
15.

The system of linear equations x+y+z=2 2x+y-z=3 3x+2y+kz=4 has a unique solution if

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`KNE0`
`-1ltklt1`
`-2ltklt2`
k=o

Answer :A
16.

It is given that at x = 1, the function x^(4)-62x^(2)+ax+9 attains its maximum value, on the interval [0, 2]. Find the value of a.

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ANSWER :120
17.

Solve as directed : 7(x-3) le 4 (x +6 ), for non-negative integral values.

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Solution :7(X-3) `le` 4 (x +6 )
`rArr 7x - 21 le 4X + 24`
`rArr 7x - 4x le 24 + 21`
`3X le 45`
`x le 9`
If x is a non negative integer the solution setis
S = {0,1,2,3,4,5,5,6,7,8,9}
18.

Express the following as trigonometric ratios of some acute angles. cosec (-60^@)

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SOLUTION :`COSEC (-60^@) = -cosec 60^@`
19.

A six letters word is formed using the letters of the word LOGARITHEM with or without repetition. Find the number of words that contain exactly three different letters.

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Solution :We have letters L, O, G, A, R, I, T, H, M.
Words contain exactly THREE different letters.
Three letters can be selected in `.^(9)C_(3)` ways.
Now we have following cases for the occurrence of these three letters.
Case I : Occurrence of letters is 4,1,1
The letter which is occurring four TIMES can be selected in `.^(3)C_(1)` ways.
Then letters can be arranged in `(6!)/(4!)` ways.
So, number of words in this case are `.^(3)C_(1)xx(6!)/(4!)=90`
Case II : Occurrence of letters is 3,2,1
The letter which is occurring three times can be selected in `.^(3)C_(1)` ways.
The letter which is occurring two times can be selected in `.^(2)C_(1)` ways.
Then letters can be arranged in `(6!)/(3!2!)` ways.
So, number of words in this case are `.^(3)C_(1)xx .^(2)C_(1)xx(6!)/(3!2!)=360`
Case III : Occurrence of letters is 2,2,2
Since each letters is occurring TWICE, number of words are `(6!)/(2!2!2!)=90`
So, TOTAL number of words `=.^(9)C_(3)xx(90+360+90)`
`=84xx540`
=45360
20.

If the inverse of the matrix A=[{:(3, 4, 5), (2, -1, 8), (5, -2, 7):}] is B, then B^(T)=

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`1/136[{:(9, 26, 1), (-38, -4, 26), (37, -14, -11):}]`
`1/136[{:(9, -38, 37), (26, -4, -14), (1, 26, -11):}]`
`1/136[{:(9, 26, 1), (37, -14, -11), (-38, -4, 26):}]`
`1/136[{:(9, 1, 26), (-38, 26, -4), (37, -11, -14):}]`

Answer :A
21.

Let the circle x^(2) + y^(2) + alpha x + beta y + 5 = 0meets the rectangular hyperbola xy = c^(2) at four points A, B, C , D . The equation of the circumcircle of the triangle formed by joining the orthocentres of the triangles ABC, ABD and ACD is , x^(2) + y^(2) + 2gx + 2fy + k = 0. If alpha + beta= 6 , then the value of (g + f + k), is ________

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SOLUTION :N/A
22.

A manufacturer has 75kg of cashew nuts and 120kg of peanuts. These are mixed and packed into 1 kg packages as follows. A low grade mixture that containing 250gm of cashew and 750gms of peanuts, a high grade mixture that contains 500 gms of cashew and 500 gms of peanuts. On the low grade mixture the manufacturer gets a profit of 25 paise per package, while on the high grade the profit is 45 paise per package. How many packages of each mixture should be made to obtain a maximum profit?

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90105
90160
105150
90150

Answer :A
23.

Find the rate of change of the area of a circle with respect to its radius r when r=5cm.

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24.

A factory is operating in two shifts, day and night with 70 and 30 workers respectively. If per day mean wage of the day shift workers is rupes 54 and per day mean wages of all the workers is rupes 60 , Then per day mean wages of the night shift (in Rs.)is :

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66
69
74
75

Answer :C
25.

The vectors, p=(a+1)i+aj+ak, q=ai+(a+1)j+ak" and "r=ai+aj+(a+q)k. If 3(p.q)^(2)-lambdaabs(r times q)^(2)=0, then the value of lambda is _______

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ANSWER :1
26.

If y = sqrt(((x-1)(x-2))/((x-3)(x-4)(x-5))) find (dy)/(dx)

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ANSWER :`(1)/(2)SQRT(((x-1)(x-2))/((x-3)(x-4)(x-5)))[(1)/(x-1)+(1)/(x-2)-(1)/(x-3)-(1)/(x-4)-(1)/(x-5)]`
27.

If f : [0,3] to [0,3] is defined by f (x) ={{:(1+x,0lt=xlt=2),(3-x,2ltxlt=3):}then fofo is

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Conrinuous at x = 1
CONTINUOUS at x =2
Discontinuous at x =1 and x=2
Continuous on [0,3]

ANSWER :C
28.

Let f(x) = (arc tan x)^(3) + (arc cot x)^(3) .If the range of f (x) is [a,b), then find the value of b/(7a).

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ANSWER :4
29.

Let f(x) = tan^(-1) x and g(x) = (x)/(1 + x^(2)), x gt 0 then

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`f(x) lt g (x), " on "(0, oo)`
`f(x) LE g (x) " on "[1, oo)`
`g (x) lt f(x) " on "(0, oo)`
NONE of these

Answer :C
30.

Find the area of the triangle formed by the tangent at P(x_(1), y_(1)) to the circle x^(2) +y^(2) = a^(2) with co-ordinate axes where x-(1) y_(1) ne 0.

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ANSWER :` (a^(4))/(2|x_1y_1|) `
31.

Is ** defined on the set {1,2,3,4,5} by a ** b =L.C.M. of a and b a binary opertion ? Justified your answer.

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ANSWER :NO
32.

Compute theintegrals I = int_(0)^(1) sqrt(2 x - x^(2)) dx

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Answer :`sqrt(3) -0 . 5 I N (2 + sqrt(3))`
33.

If A is a matrix of order 3xx3, then (A^2)^(-1)="........."

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ANSWER :`(A^2)^(-1)=(A^(-1))^2`
34.

Sum of the focal distance of the ellipse (x^2)/(a^2) + (y^2)/(b^2) = 1 is

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`(B^(2)/C, (a^(2)m)/c)`
`(-(a^(2)m)/c, b^(2)/c)`
`((a^(2)m)/c, -b^(2)/c)`
`((-a^(2)m)/c, -b^(2)/c)`

ANSWER :B
35.

The system of equations 2x-y+z=0 x-2y+z=0 x-y+2z=0 has infinite of nontrivial solutions for

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`=1`
`=5`
`=-5`
no REAL value of

ANSWER :B
36.

If A+B+C+D=360^(@) then show that sinA-B+sinC-sinD= -4cos((A+B)/2)cos((A+D)/2)sin((A+C)/2)

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ANSWER :RHS
37.

Let veca = 2hati+hatj, vecb = -hati+3hatj+hatk and vecc = hati+2hatj+5hatk be three vectors. Find (veca-vecb)xx(vecc-veca)

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SOLUTION :
=`HATI(-10+1)-HATJ(15-1)+HATK(3-2)`
=`-9hati-14hatj+hatk`
38.

At an election, a voter may vote for any number of candidates, not greater than the number to be elected. There are 10 candidates and 4 are to be elected. If a voter votes for at least one candidate, then the number of ways in which he can vote is

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5040
6210
385
1110

Answer :C
39.

Evaluate int sin^(4) x cos^(5) x dx

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Answer :`-(sin^(2)XCOS^(5)X)/(7)-(2)/(35)cos^(5)x+c`
40.

Rob spends (1)/(2) of his monthly paycheck, after taxes,on rent. He spends (1)/(3) on food and (1)/(8) on entertainment. If he donates the entire remainder, $500, to charity, what is Rob's monthly income, after taxes?

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ANSWER :`$12,000`
41.

If the Roofean expression ( p oplus q ) ^^ ( ~ p odot q ) is equivelent ot p ^^ q where oplus , odot in( ^^ , vee ) , then the ordered pair (oplus, odot)is equal to

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`(VEE , ^^) `
`(vee, vee)`
`(^^, vee) `
`(^^, ^^)`

ANSWER :C
42.

Let P(x)=|(x^(2)-13,4,2),(3,x^(2)-13,7),(6,5,x^(2)-13)| If x=-2 is a zero of P(x), then sum of the remaining five zerord id

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`-2`
`0`
`2`
`3`

ANSWER :C
43.

Find the transberes common tangents of the circles x^(2) + y^(2) -4x -10y + 28 = 0and x^(2) + y^(2)+ 4x - 6y + 4 0.

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ANSWER :`x-1 =0, 3X+ 4Y -21=0 `
44.

The perimeter of a DeltaABC is 48 cm and one side is 20 cm. Then remaining sides of DeltaABC must be greaterthan :

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8 CM
9 cm
12 cm
4 cm

Answer :D
45.

Let f(x)=int_(0)^(x) (sint-cost)(e^t-2)(t-1)^3(t-1)^3(t-2)^5 dt , 0lt xle4 Then , the number of points where f(x) assumes local maximum value , is

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1
2
3
none of these

SOLUTION :We have`f(x)=oversetxunderset0int(sint-cost)(e^t-2)(t-1)^3(t-1)^3(t-2)^5 dt , 0lt xle4`
`rArr f'(x)=oversetxunderset0int(sint-cost)(e^t-2)(x-1)^3(x-2)^5,0ltxle4`
for local maximum or minimum , we must have
f'(x)=0
`rArr sinx-cosx=0,e^x-2=0,(x-1)^3=0,(x-2)^5=0`
`rArr tanx=1,e^x=2,x=1,2`
`rArr x=5/4,(5pi)/4,x=log_e2,x=1,2 "" [therefore0 lt xle 4]`
`rArrx=0.785,3.925,0.693,1,2`
The changes in SIGN s of f'(x) in the nieghbourhoods of these POINTS are shown in Fig.17.
CLEARLY `x=log_e2,pi/4 and (5pi)/4` are points of local maxima
46.

If A and B are two events such that P(A|B)=0.6, P(B|A)=0.3, P(A)=0.1 then P(barAnnbarB)=

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`0.88`
`0.12`
`0.6`
`0.4`

ANSWER :A
47.

If C=[{:(,1,4,6),(,7,2,5),(,9,8,3):}] [{:(,0,2,3),(,-2,0,4),(,-3,-4,0):}] [{:(,1,7,9),(,4,2,8),(,6,5,3):}] Then trace of C+C^(3)+C^(5)+……+C^(99) is

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ANSWER :ZERO
48.

A salesman has a 60% chance of making a sale to each customer. The behaviour of successive customers is independent. If two customers A and B enter. The probability that the salesman will make a sale to A or B is

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`0.36`
`0.84`
`0.96`
`0.74`

ANSWER :B
49.

Consider parabola P_(1)-=y=x^(2) and P_(2)-=y^(2)=-8x and the line L-=lx+my+n=0.Which of the following holds true (a point (alpha,beta) is called rational point if alpha and beta are rational)

Answer»

If `l,m,n` are odd integers then the line `L` can not intersect parabola `P_(1)` in a rational point.
Line `L` will be tangent to `P_(1)` if `m,l/2,n` are in G.P.
If line `L` is COMMON tangent to `P_(1)` and `P_(2)` then `l+m+n=0`
If line `L` is common chord of `P_(1)` and `P_(2)` then `l-2m+n=0`

Solution :Point of intersection of `P_(1)` and `L` is GIVEN by `mx^(2)+lx+n=0`
Line is tangent of `l^(2)=4mnimpliesm,l/2,n` are in G.P.
If point of intersection is rational (let `x=p/q`) where `p` and `q` are co-prime.
Then `mp^(2)+lpq+nq^(2)=0`…….(1)
Now if onne of `p` and `q` is even and other is odd then (1) cannot hold as sum of an even and an odd integer can't be zero.
If `p,q` are odd then (1) cannot hold true as sum of three odd numbers can't be zero.
Common tangent to `P_(1)` and is `2x-y-1=0`
Common chord of `P_(1)` and `P_(2)` is `2x+y=0`
50.

Which of the following graphs represent function whose derivatives have a maximum in the interval (0,1) ?

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ANSWER :A::B