{:("Column A", "Column B"),("The average of the sum of the square of the", (a) 5:1),("first five natural numbers is ",),("If" x = 5y", then "x:y" is", (b)20%),("The cost price of an article is Rs. 200 and its", (c) 10%),("selling price is Rs. 180. Find the loss percentage.",),("At what rate of interest will Rs. 250 amount to ", (d) 11),("triple its present value in 10 years at simple ",),("interest(p.a)%",),(,(e) 1:5),(,(f) 15%),(,(g) 10):}

{:("Column A", "Column B"),("The average of the sum of the square of t

1.	{:("Column A", "Column B"),("The average of the sum of the square of the", (a) 5:1),("first five natural numbers is ",),("If" x = 5y", then "x:y" is", (b)20%),("The cost price of an article is Rs. 200 and its", (c) 10%),("selling price is Rs. 180. Find the loss percentage.",),("At what rate of interest will Rs. 250 amount to ", (d) 11),("triple its present value in 10 years at simple ",),("interest(p.a)%",),(,(e) 1:5),(,(f) 15%),(,(g) 10):}
Answer» SOLUTION :`(d): " Average " = (1^(2) + 2^(2) + 3^(2) + 4^(2) + 5^(2))/(5)` `= (1 + 4 + 9 + 16 + 25)/(5) = (55)/(5) = 11` `(a) : x = 5y rArr (x)/(y) =(5)/(1) rArr x:y = 5:1` `(c): CP = Rs. 200, SP = Rs. 180, " Loss" = Rs. 20` `" The loss percentage " = (20)/(200) xx 100% = 10%` `(b): " Principal "= Rs. 250` Amount = Rs. 750 Simple Interest = Rs. 500 Rate = ? TIME= 10 Years `rArr = 500 = (250 xx R xx 10)/(100)` R = 20%1