Question

24. Certain sum of money borrowed at simple interest amount to Rs 2688 in three years and to Rs.2784 in
four years at the rate per annum equal to
(a) 79%
(b) 6%
(c) 5%​

Answer 1

Answer:

4%

Explanation:

Amount in 3 years = Rs. 2688

Amount in 4 years = Rs. 2784

Thus, interest per year = 2784 - 2688 = Rs. 96

Principal amount = 2688 - (3 x 96) = Rs. 2400

Interest percentage = 96 / 2400 = 4%

Answer 2

The annual rate of interest is 4%.

GIVEN: Simple Interest amount after three years= 2688 Simple Interest amount after four years = 2784

TO FIND: Interest rate

SOLUTION:

Compare and contrast simple interests.

Straightforward interest in four years: 2784

Three years at simple interest: 2688

Basic interest over a year= 2784 - 2688              

                                           = 96

Therefore, the annual simple interest rate is 96.

Determine the principal sum.

Three years of simple interest = 3 × 96

                                                  = 288

Primary Amount = 2688 - 288

                           = 2400

Thus,

The principal is 2400.

Find the interest rate.

Total principal: 2400

Time= Three years.

Interest only: 288

Rate = $\frac{288*100}{2400*3}$

      = 4%

We have calculated the rate by using the formulae PRT/100.

The annual rate of interest is 4%.

CORRECT QUESTION-

A certain sum of money borrowed at simple interest amount to Rs.2688 in three years and Rs.2784 in

four years at the rate per annum equal to

a. 7%

b. 6%

c. 5%

d. 4%

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