OTTUIUIU-JIE 6.The difference between the compound interest, compounde

1.	OTTUIUIU-JIE 6.The difference between the compound interest, compounded andsimple interest on a certain sum for 2 years at 15% per annumthe sum.180. Find2 years at 15% per annum is
Answer» Let ₹P be the principal. Then, S.I. = P×R×T/100 = P×15×2/100 = ₹3P/10 C.I. = P{(1+R/100)^n - 1} = P{(1+15/100)^2 - 1} = P{(100+15/100)^2 - 1 = P{(115/100)^2 - 1} = P{(23/20)^2 - 1} = P{529/400 - 1} = P{529 - 400/400} = P{129/400} = ₹129P/400 According to question, C.I. - S.I. = 180 => 129P/400 - 3P/10 = 180 => 129P - 120P/400 = 180 => 9P/400 = 180 => P = 180×400/9 => P = ₹8,000 Hence, the sum is ₹8,000.

OTTUIUIU-JIE 6.The difference between the compound interest, compounded andsimple interest on a certain sum for 2 years at 15% per annumthe sum.180. Find2 years at 15% per annum is

Answer»

Let ₹P be the principal. Then,

S.I. = P×R×T/100

= P×15×2/100

= ₹3P/10

C.I. = P{(1+R/100)^n - 1}

= P{(1+15/100)^2 - 1}

= P{(100+15/100)^2 - 1

= P{(115/100)^2 - 1}

= P{(23/20)^2 - 1}

= P{529/400 - 1}

= P{529 - 400/400}

= P{129/400}

= ₹129P/400

According to question,

C.I. - S.I. = 180

=> 129P/400 - 3P/10 = 180

=> 129P - 120P/400 = 180

=> 9P/400 = 180

=> P = 180×400/9

=> P = ₹8,000

Hence, the sum is ₹8,000.