Question 1

The principal that amounts to Rs.4913 in 3 years at 413 % per annum compound interest compounded annually is

Accepted Answer

principal = A = 4913 , T = 3 , R = 4 1 3 P = A 1 + R 100 T = Rs.4096

Question 2

A certain sum is invested for 2 years in scheme M at 20% p.a. compound interest (compounded annually), Same sum is also invested for the same period in scheme N at k% p.a. simple interest. The interest earned from scheme M is twice of that earned fr…

Accepted Answer

Interest earned in scheme M = P 1 + 20 100 2 - 1 = 11 P 25 Interest earned in scheme N = P x k x 2 100 = P k 50 Now, from the given data, 11 P 25 = 2 x P k 50 k = 11

Question 3

The present worth of Rs.169 due in 2 years at 4% per annum compound interest is

Accepted Answer

Present Worth = P 1 + R 100 2 = 169 1 + 4 100 2 = Rs.156.25

Question 4

Find the compound interest on Rs. 6,500 for 4 years if the rate of interest is 10% p.a. for the first 2 years and 20% per annum for the next 2 years?

Accepted Answer

We know the formula for calculating The compound interest C = P 1 + r 100 n - 1 where P = amount, r = rate of interest, n = time Here P = 5000, r1 = 10, r2 = 20 Then C = 6500 1 + 10 100 2 x 1 + 20 100 2 - 1 = 6500 x 1856 2500 = 65 x 1856 25 C = Rs. 4826.

Question 5

What is the interest rate per annum, if a sum of money invested at compound interest amount to Rs. 2400 in 3 years and in 4 years to Rs. 2,520?

Accepted Answer

Let 'R%' be the rate of interest From the given data, 2520 2400 = 1 + R 100 4 1 + R 100 3 ⇒ 1 + R 100 = 63 60 ⇒ R = 5 Hence, the rate of interest R = 5% per annum.

Question 6

A sum is equally invested in two different schemes on CI at the rate of 15% and 20% for two years. If interest gained from the sum invested at 20% is Rs. 528.75 more than the sum invested at 15%, find the total sum?

Accepted Answer

Let Rs. K invested in each scheme Two years C.I on 20% = 20 + 20 + 20x20/100 = 44% Two years C.I on 15% = 15 + 15 + 15x15/100 = 32.25% Now, (P x 44/100) - (P x 32.25/100) = 528.75 => 11.75 P = 52875 => P = Rs. 4500 Hence, total invested money = P + P = 4500 + 4500 = Rs. 9000.

Question 7

The compound interest on Rs. 8000 for 3 year at 10% p.a. is

Accepted Answer

8000 × 33.1% = 2648

Question 8

What is the difference between the compound interests on Rs. 5000 for 1 1/2 years at 4% per annum compounded yearly and half-yearly?

Accepted Answer

C.I. when interest compounded yearly=rs.[5000*(1+4/100)(1+1/2*4/100)] = Rs. 5304. C.I. when interest is compounded half-yearly=rs.5000(1+2/100)^3 = Rs. 5306.04 Difference = Rs. (5306.04 - 5304) = Rs. 2.04

Question 9

At a certain rate of interest the compound interest of 3 years and simple interest of 5 years for certain sum of money is respectively Rs. 1513.2 and Rs. 2400. Find the common rate of interest per annum ?

Accepted Answer

Given compound interest for 3 years = Rs. 1513.2 and simple interest for 5 years = Rs. 2400 Now, we know that C.I = P 1 + R 100 n - 1 => 1513.2 = P 1 + R 100 3 - 1 ...........(A) And S.I = PTR/100 => 2400 = P5R/100 ..................(B) By solving (A) & (B), we get R = 5%.

Question 10

What will be the compound interest on a sum of Rs.25,000 after 3 years at the rate of 12 p.c.p.a?

Accepted Answer

Amount = Rs.(25000x(1+12/100)³ = Rs.(25000x28/25x28/25x28/25) = Rs. 35123.20. C.I = Rs(35123.20 -25000) = Rs.10123.20

Question 11

Rs. 5887 is divided between Shyam and Ram, such that Shyam's share at the end of 9 years is equal to Ram's share at the end of 11 years, compounded annually at the rate of 5%. Find the share of Shyam.

Accepted Answer

Shyam's share * (1+0.05)9 = Ram's share * (1 + 0.05)11 Shyam's share / Ram's share = (1 + 0.05)11 / (1+ 0.05)9 = (1+ 0.05)2 = 441/400 Therefore Shyam's share = (441/841) * 5887 = 3087

Question 12

The difference between the compound interest and simple interest on a certain sum at 10% per annum for 2 years is Rs. 631. Find the sum.

Accepted Answer

Let the sum be Rs. x. Then, C.I. = x ( 1 + ( 10 /100 ))^2 - x = 21x / 100 , S.I. = (( x * 10 * 2) / 100) = x / 5 (C.I) - (S.I) = ((21x / 100 ) - (x / 5 )) = x / 100 ( x / 100 ) = 632 * x = 63100. Hence, the sum is Rs.63,100.

Question 13

The difference between the compound interest and simple interest on a certain sum at 10% per annum for 2 years is Rs. 631. Find the sum.

Accepted Answer

Let the sum be Rs. x. Then, C.I. = x ( 1 + ( 10 /100 ))^2 - x = 21x / 100 , S.I. = (( x * 10 * 2) / 100) = x / 5 (C.I) - (S.I) = ((21x / 100 ) - (x / 5 )) = x / 100 ( x / 100 ) = 632 * x = 63100. Hence, the sum is Rs.63,100.

Question 14

Rs 1000 is being charged at 50% per annum. what is the interest for 3rd year at compound interest?

Accepted Answer

Total amount for two years = 1000 × 1 . 5 2 = 2250 Now , interest for third year = 2250 × 50 × 1 100 = 1125

Question 15

The minimum number of half years in which a sum of money kept at 60% compound interest will be quadrupled is ?

Accepted Answer

Let us assume Amount be 100 Rs and we calculate in CI First year 60% of 100 = 60 amount (100+60) is 160 Second year 60% of 160 = 96 amount (160+96) is 256 Third year 60% of 256 =153.6 amount (256+153.6) is 409.6 Here the Amount of 100 Rs is quadrapled in 3 years. One year contains 2 half years Three year has 6 half years. Therefore, It takes 6 half years.

Question 16

A sum of money invested at compound interest amounts to Rs. 800 in 3 years and to Rs. 840 in 4 years. The rate of interest per annum is

Accepted Answer

S.I. on Rs.800 for 1 year =Rs[840 - 800] = Rs.40 Rate =(100x40/800x1)% = 5%

Question 17

What is the SI on Rs.2500/- at the rate of 12% per annum for 8 years?

Accepted Answer

S.I=PNR/100

Question 18

Find the compound interest on Rs. 2680 at 8% per annum for 2 years ?

Accepted Answer

We know Compound Interest = C.I. = P1+r100t - 1 Here P = 2680, r = 8 and t = 2 C.I. = 26801 + 81002-1= 268027252-12= 26802725+12725-1= 2680 5225×225 = (2680 x 52 x 2)/625 = 445.95 Compound Interest = Rs. 445.95

Compound Interest Questions