- « Previous Page
- 1
- 2
- 3
- 4
- 5
- …
- 9
- Next Page »

A Learning Portal from Recruitment India

You are Here :
Home » Aptitude » Compound Interest » Page 3

The difference between compound interest and simple interest at the same rate on Rs 5000 for 2 years is Rs 72. The rate of interest per annum is:

A.

6%

B.

8%

C.

10%

D.

12%

Answer with explanation

Answer: Option DExplanation

Let the rate be r % p.a,

Then S. I = Rs (5000 × r/100 × 2) = Rs (100r)

C. I = Rs[5000 × (1 + r/100) ^{2} – 5000]

= Rs {5000 × [(1 + r/100) ^{2} – 1]}

= Rs [5000 × (r^{2}/2 + r/50)]

= Rs (r^{2} /2 + 100r)

(C.I) – (S.I) = (r^{2}/2 + 100r) – (100r) = r^{2}/2

Therefore, r^{2}/2 = 72

=> r^{2} = 144

=> r = 12

Hence, Rate = 12 % p.a

Workspace

The compound interest earned by Sunil on a certain amount at the end of two years at the rate of 8% p.a. was Rs.2828.80. Find the total amount that Sunil got back at the end of two years in the form of principal plus interest earned.

A.

Rs.18,828.80

B.

Rs.19,828.80

C.

Rs.18,028.80

D.

Rs.17,828.80

Answer with explanation

Answer: Option BExplanation

Let the sum be Rs.P

P{ [ 1 + 8/100]^{2} – 1 } = 2828.80

P(8/100)(2 + 8/100) = 2828.80 [a^{2} – b^{2} = (a – b) ( a + b)] P = 2828.80 / (0.08)(2.08) = 1360/0.08 = 17000 Principal + Interest = Rs. 19828.80

Workspace

If you can choose how frequently the interest rate on a loan is compounded that you have to pay back to someone else. In order to pay the least amount of interest would you want it rather to:

A.

compound monthly

B.

annually

C.

half-yearly

D.

it makes no difference

Answer with explanation

Answer: Option BExplanation

By compounding annually you would pay less interest than monthly compounding for example so B is the right answer.

Workspace

Find the compound interest on `25625 for 12 months at 16% per annum, compound quarterly.

A.

4352.62

B.

4252.36

C.

4562.63

D.

4456.23

Answer with explanation

Answer: Option AExplanation

Principal(P)= `25625

Rate(r) = 16% =16/4% = 4%

Time = 12 months = 4 quaters

A = 25625(1+4/100)^4 = 25625(26/25)^4= 25625×26/25×26/25×26/25×26/25=29977.62

C.I. =A-P = 29977.62-25625 = **4352.62**

Workspace

- « Previous Page
- 1
- 2
- 3
- 4
- 5
- …
- 9
- Next Page »

Correct Answer 👍

Wrong Answer 👎