A certain amount of money becomes ? 944 in three years by earning simple interest. If the rate of interest is increased by25%, the amount would become ? 980 during the same period. What was the principal amount ?

` 600
` 800
` 860
` 700

The correct answer is (a) ` 600.

Let P be the principal amount.

The simple interest for 3 years is 944 – P.

The simple interest for 3 years at 25% higher rate is 980 – P.

The simple interest is proportional to the principal amount and the rate of interest and the time period.

So, we have the following equations:

944 – P = (P)(R)(3)

980 – P =

132.3c6.3 23.7 24.8 41.5 48.3 47.8C117.2 448 288 448 288 448s170.8 0 213.4-11.5c23.5-6.3 42-24.2 48.3-47.8 11.4-42.9 11.4-132.3 11.4-132.3s0-89.4-11.4-132.3zm-317.5 213.5V175.2l142.7 81.2-142.7 81.2z"/> Subscribe on YouTube
(1.25)(P)(R)(3)

Solving the above equations, we get P = 600.

The other options are incorrect because they are not the principal amount.