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1.

The box alongside shows the number called Googol. Try to write it as a power of 10.

Answer»

According to question box 

 1 x 10100

2.

Try to write the following numbers in the standard form.i. The diameter of Sun is 1400000000 m. ii. The velocity of light is 300000000 m/sec.

Answer»

i. 1400000000 m = 1.4 x 109

ii. 300000000 m/s = 3.0 x 108 m/sec.

3.

Write the following numbers using positive indices:i. (2/7)-2ii. (11/3)-5iii. (1/6)-3iv. (y)-4

Answer»

i. (7/2)2

ii. (3/11)-5

iii. 63

iv. 1/y4

4.

Simplify:i. a6 ÷ a4ii. m5 ÷ m8iii. p3 ÷ p13iv. x10 ÷ x10

Answer»

i. a6 ÷ a

= a6-4

= a2

ii. m5 ÷ m8

= m5-8

= m-3

iii. p3 ÷ p13

= p3 - 13

= p-10

iv. x10 ÷ x10

= x10-10

= x0

= 1

5.

Velocity of light is `30,000,000,000 cm//sec`. Its value by using powers of 10 is ______A. `3xx10^8cm//s`B. `3xx10^9cm//s`C. `3xx10^10cm//s`D. `3xx10^11cm//s`

Answer» Correct Answer - C
NA
6.

Find the value of `(2^4+2^3)^(2//6)`A. `8(2)^(1//2)`B. `2(3)^(1//3)`C. `64(2)^(1//2)`D. `4(3)^(1//3)`

Answer» Correct Answer - B
Given ,
`(2^4+2^3)^(2)/(6)`
`=(2^4+2^3)^(1)/(3)=[2^3(2+1)]^(1//3)`
`=2^(3//3)(3)^(1//3)=2(3)^(1//3)`
Hence, the correct options is (b) .
7.

`(0.000729)^(1/3) = `______A. `0.030`B. `sqrt(0.09)`C. `0.18`D. `0.09`

Answer» Correct Answer - D
NA
8.

If `a+b+c=0`, then find the value of `(x^(a))^(3)/(x^(-3b)x^(-3c))`

Answer» Correct Answer - B
NA
9.

Simplifty `(sqrt(144)+sqrt(256))/(3^2-2)`A. 8B. 4C. `-4`D. `-8`

Answer» Correct Answer - B
NA
10.

If ` a=36`, then find the value of `a^(36^@)-a^(0^36)`.A. 36B. 0C. 1D. 35

Answer» Correct Answer - D
NA
11.

`(25^2-15^2)^((3)/(2))=` _____A. 4000B. 8000C. 3125D. 1024

Answer» Correct Answer - B
Given
`(25^2-15^2)^(3//2)`
`=[(25+15)(25-15)]^(3//2)`
`=[40xx10]^(3//2)=[2^2xx10^2]^(3//2)=(20)^3=8000`
Hence, the correct options is (b).
12.

`(33^2-31^2)^((5)/(7))=` _____A. 64B. 16C. 32D. 4

Answer» Correct Answer - C
`(33^2-31^2)^(5//7)`
` =[(33+31)(33-31)]^(5//7)`
`=[64xx2]^(5//7)`
`=(2^7)^(5//7) =2^5=32`
Hence, the correct options is (c) .
13.

If `abc=0`, then find the value of `([(x^(a))^(b)]^(2c))/(x^(abc))`A. 3B. 0C. `-1`D. 1

Answer» Correct Answer - D
NA
14.

If `abc =0` then find the value of `[(x^a)^b]^c`.A. 1B. aC. bD. c

Answer» Correct Answer - A
Gven `abc=0`
`[(x^a)^b]^c`.
`=(x^a)^(bc)`
`=x^(abc)`
`=x^0=1`
Hence, the correct options is (a).
15.

If `a+b+c=0`, then find the value of `sqrt(x^a.x^b.x^c)`.

Answer» Correct Answer - B
Given `a+b+c=0`.
`sqrt(x^ax^b.x^c)`
`=sqrt(x^(a+b+c))=sqrt(x^0)=sqrt(1)=1`
Hence, the correct options is (b).
16.

If `xyz=0`, then find the value of `[(k^(x))^y]^z-[(k^(y))^z]^x-[(k^(z))^x]^(y)`

Answer» Correct Answer - `-1`
NA
17.

Simplify `(sqrt(36)+sqrt(64))/(2^3-1)`.A. 1B. 2C. 3D. 4

Answer» Correct Answer - B
`(sqrt(36)+sqrt(64))/(2^3-1)`
`=(sqrt(6^2)+sqrt(8^2))/(2^3-1)=(6+8)/(8-1)=(14)/(7)=2`
Hence, the correct options is (b).
18.

Evaluate `a^(n)`.A. 64B. 128C. 32D. 256

Answer» Correct Answer - B
(a) Evaluate `(1^(2)+2^(2)+3^(2))` and express it as the exponent of the single number.
(b) Simplify and get the result.
19.

By what number should `(8//27)^(-3)` be a divided to that the quotient is equal to `(27//8)^(-3)` ?

Answer» Correct Answer - `((3)/(2))^(18)`
NA
20.

If `a=25` ,then find the value of `a^(25^(0))+a^(0^(25))`.A. 25B. 26C. 24D. 0

Answer» Correct Answer - B
Given `a=25`,
`a^(25^(0))+a^(0^(25))=a^1+a^0`
`=a+1=25+1=26`
Hence, the correct options is (b).
21.

`(21^(2)-15^(2))^(4/3)=`A. `36 root(3)(6)`B. `1296`C. `root(3)(1296)`D. `(root(3)(6))^(4)`

Answer» Correct Answer - B
Recall `(a+b) (a-b)=a^(2)-b^(2)`.
22.

By what number should we multiply `3^4` so that the product is equal to `(1)/(27)`?

Answer» Correct Answer - `3^(-7)`
NA
23.

If `2^(7x-5)=(32)^(x-7)`, then find the value of `(1)/(2^x)`A. `2^17`B. `2^16`C. `2^15`D. None of these

Answer» Correct Answer - C
Given `2^(7x-5)=(32)^(x-7)`
`rArr 2^(7x-5)=2^(5x-35) (because 32=2^5)`
`rArr 7x-5=5x=35`
`rArr 2x=-30`
`rArr x=-15`
`therefore (1)/(2^x)=(1)/(2^-15)=2^15`
Hence , the correct option is (c).
24.

If `9^(2x-7)=(27)^(x-4)`, then find the value of `3^x`.

Answer» Correct Answer - 9
NA
25.

What should be multiplied to `3^(-4)` so that product is 6 ?

Answer» Correct Answer - 486
NA
26.

Simplify `(3x^(-2)y^(-3)z^(2)xx5x^(2)xxyxxz^3 )÷x^(3)y^(2)z^(-1)`

Answer» Correct Answer - `15x^(-3)y^(-4)z^(6)`
NA
27.

Vicky scored x marks in Maths and Rakesh scored `x^3` marks in Maths. The proudct of their marks was 256. Find their marks.

Answer» Correct Answer - 4,64
NA
28.

If `xyz=0` , then find the value of `(a^x)^(zy)+(a^y)^(zx)+(a^z)^(xy)`.A. 3B. 2C. 1D. 0

Answer» Correct Answer - A
Given `xyz=0`
`(a^x)^(zy) +(a^y)^(zx)+(a^z)^(xy)`
`=a^(xyz)+a^(xyz)=a^(0)+a^(0)+a^(0)`
`1+1+1=3`
Hence , the correct option is (a).
29.

What should be multiplied to `2^6` so that the products is 1 ?A. 16B. 32C. 64D. 128

Answer» Correct Answer - C
Let the required number be `x`.
`therefore x xx 2 ^(-6)=1`
`rArr x((1)/(2^6))=1`
`rArr x=1xx2^6=2^6=64`
Hence the correct option is (c).
30.

Varun secured x marks in Maths and Rahul secured `x^2` marks in Maths. The product of their marks was 729. Find their marks.A. `3,243`B. `9,81`C. `27,27`D. None of these

Answer» Correct Answer - B
Marks secured by Varun =x.
Marks secured by Rahul `=x^2`.
Given `x.x^2=729`.
`x^3=729`
`x^3=9^3`
`therefore x =9`
Marks securd by Varun `=x=9`
Marks secured by Rahul `=x^2=9^2=81`
Hence , the correct option is (b).
31.

`64^(2/3)xx64^(1/3)xx64^((-5)/3)`A. `1/64`B. `1/16`C. 32D. `1/32`

Answer» Correct Answer - B
Apply laws of indices.
32.

`root(6)(0.004096)=`A. 0.2B. 0.4C. 0.6D. 0.8

Answer» Correct Answer - B
Apply prime factorisation.
33.

If `(sqrt(3))^(x+y)=9` and `(sqrt(2))^(x-y)=32`, then `2x+y` is _______.A. 1B. 0C. 17D. 11

Answer» Correct Answer - D
Given,
`(sqrt(3))^(x+y)=9` and `(sqrt(2))^(x-y)=32`
`implies 3^((x+y)/2)=3^(2)` and `2^((x-y)/2)=2^(5)`
`implies (x+y)/2=2` and `(x-y)/2=5`
`implies x+y=4` (1)
and `x-y=10` (2)
Solving (1) and (2), we get
`x=7` and `y=-3`
Now, `2x+y=2(7)-3=11`.
34.

If `6^(x-y)=36` and `3^(x+y)=729`, then find `x^(2)-y^(2)`.A. 12B. 4C. 24D. 8

Answer» Correct Answer - A
`6^(x-y)=36`
`6^(x-y)=6^(2)`
`:. x-y=2` (1)
and `3^(x+y)=3^(6) implies x+y=6` (2)
From (1) and (2), `x^(2)-y^(2)=12`.
35.

Find the value of `[[a/b]^(sqrt(99)-sqrt(97))]^(sqrt(99)+sqrt(97))`A. `b^(2)/a^(2)`B. `sqrt(b/a)`C. `sqrt(b/a)`D. `a^(2)/b^(2)`

Answer» Correct Answer - D
Apply laws of exponents.
36.

Find value of `(61^(2)-11^(2))^(3/2)`.A. `50^(3)`B. `216000`C. 3600D. 60

Answer» Correct Answer - B
Use the identity `a^(2)-b^(2)=(a+b) (a-b)`
37.

If `3^x=9^y=27^(z)=729`, then show that `x+y+z=11`.

Answer» Correct Answer - NA
NA
38.

If `11^x = 3^y = 99^z`, then `1/x + 1/y + 1/z`A. `2/z-1/y`B. `2/z+1/y`C. `-1/y`D. `0`

Answer» Correct Answer - A
(i) Let each of the three given terms be equal to K.
(ii) Take the LCM of each term of numerator and denominator.
(iii) Simplify using the appropriate laws of indices.
39.

If `a^(b^t) = 6561`, then find the least possible value of `(a.b.c)`, where `a, b and c` are integers.A. 24B. 36C. 162D. None of these

Answer» Correct Answer - D
(i) Express 6561 as the different ways of exponential forms.
(ii) x is of the form `a+b`.
(iii) `y` is of the form `a^(2)+ab+b^(2)`.
40.

Which is the least among `(3)^25, (9)^12, (27)^3`, and `(81)^2` ?

Answer» Correct Answer - `(81)^2`
NA
41.

Find the value of `(-1)^(301)+(-1)^(302)+(-1)^(303)+.......+(-1)^(400)`.A. 1B. 101C. 100D. 0

Answer» Correct Answer - D
We know `(-1)^x`
`=-1`, when x is odd.
`=1` , when x is even.
`therefore (-1)^(301)+(-1)^(302)+....+(-1)^(400)`
`=(-1)+1+(-1)+1+...(100 " terms") =0`
Hence, the correct options is (d).
42.

Find the value of `3^4[(2/3)^2+(2/3)-(2/(3))^3]`A. 86B. 66C. 68D. 88

Answer» Correct Answer - B
`3^4[(2/3)^2+(2/3)-(2/(3))^3]`
`=3^4,(2^2)/(3^2)+3^4.(2)/(3)-3^4.(2^3)/(3^3)`
`=36+54-24=66`
Hence the correct optin is (b).
43.

If `3^x=6561`, then `3^(x-3)` is ____A. 81B. 243C. 729D. 27

Answer» Correct Answer - B
`3x=6561 =(81)^2=(3^4)=3^8`
`rArr x=8`
`3^x-3=3^8-3=3^5=243`
Hence, the correct options is (b).
44.

`2^(3^(2))=` ____A. 64B. 32C. 256D. 512

Answer» Correct Answer - D
`2^(2^(2))=2^9=512`
45.

If `(9)^(2x+4)=(243)^(2x-3.2)` , then x =_______A. 12B. 10C. 8D. 4

Answer» Correct Answer - D
Given ,
`(9)^(2x+4)=(243)^(2x-3.2)`
`rArr (3)^(4x+8)=(3)^(10x-16)`
`rArr 4x+8=10x-16`
`rArr 6x=24rArr x=4`
Hence the correct option is (d).
46.

`(2^3)^4=` _____A. `(2^(4^(3)))`B. `(2^(3^(4)))`C. `(2^(4))^(3)`D. None of these

Answer» Correct Answer - C
`(2^3)^4=2^12=(2^4)^3`
Hence ,the correct option is (c).
47.

`3^(2^(0^(5)))=`_____

Answer» Correct Answer - C
`0^5=0 and 2^0=1`
`therefore3^(2^(0^(5)))=3^1=3`
Hence,the correct option is (c).
48.

In `2x^5`, base is ____A. 2B. 2xC. xD. 5

Answer» Correct Answer - C
Base is x.
Hence, the correct options is (c) .
49.

`200000000=` _____

Answer» Correct Answer - A
`200000000=2xx10^8`
Hence ,the correct option is (a).
50.

If `2^(2n-3)=2048` , then `(4n+3n^2)=` _____.A. 175B. 25C. 125D. 75

Answer» Correct Answer - A
Given, `2^(2n-)=2048`
`rArr (2^2n)/(8)=2^11`
`rArr 2^2n=2^11 xx2^3=2^14`
`rArr n=7`
`therefore (4n+3n^2)`
`=(4xx7+3xx7^2)=175`.
Hence , the correct option is (a).