Formulas for Simple Interest Problems

Formulas based Questions on Simple Interest

Example 1.  Find the simple interest on Rs. 65,000 at 6(2/3)% per annum for a period of 9 months?

Options
(A) 3520
(B) 3250
(C) 2350
(D) 5320

Solution      Principle = 65,000

Rate = 6 \frac{2}{3} \

Time = 9 months

Principle = 65,000

Rate =  \frac{20}{3} \

Time = \frac{3}{4} \

S.I =  \frac{P*R*T}{100} \

= Rs. [65000×(20/3)×(3/4)×(1/100)]

= 3250

Correct Option(B)

Example 2. What sum of money will amount to Rs. 520 in 5 years and Rs. 568 in 7 years at simple interest?

Options
(A) 350
(B) 400
(C) 550
(D) 500

Solution     Amount in 5 years = Rs 520

Amount in 7 years = Rs 568

2 years  S.I = 568-520 = 48

Simple Interest for 1 years = \frac{48}{2} \ = 24

5 years amount = Rs 520

For 1 years = 5*24 = 120

P = A – S.I = 520-120

P = 400

                    Correct Option(B)

Read Also – Tips & tricks to solve simple interest questions