Simple Interest Practice Test – Set 1

CONCEPT USED
Simple Interest

STEP-BY-STEP SOLUTION

Let the present cash payment be P. The amount due after 6 months (0.5 years) at 9% p.a. simple interest is ₹9,810 .

$A = P * (1 + (R * T / 100))$

9810 = P * (1 + (9 * 0.5 / 100)) = P * 1.045

CONCEPT USED
Simple Interest

STEP-BY-STEP SOLUTION

Gain percentage per year = 7% - 5% = 2% per annum.

Total gain over 4 years = 2% * 4 = 8% of Principal.

CONCEPT USED
Simple Interest

STEP-BY-STEP SOLUTION

Total annual interest = 7650 / 3 = ₹2,550 .

(10500 * x / 100) + (13500 * (x + 2) / 100) = 2550

105x + 135x + 270 = 2550

240x = 2280

CONCEPT USED
Simple Interest

STEP-BY-STEP SOLUTION

Let time for first sum be t years, for second sum be (t + 2) years.

Since amounts are equal: P * (1 + 10t / 100) = P * (1 + 8(t + 2) / 100)

10t = 8t + 16

2t = 16

$t = 8 years.$

For first sum, total interest % = 10 * 8 = 80%. Amount = 180% of $P = 36900$

CONCEPT USED
Simple Interest

STEP-BY-STEP SOLUTION

SI for first 5 years = 3130 / 2 = ₹1,565 .

When principal becomes 5 times for the remaining 5 years, SI for next 5 years becomes 5 * 1565 = ₹7,825 .