At 5% p.a. simple interest, the simple interest earned by A on his investment for 4 years equals the simple interest earned by B on his investment for 6 years. If B invested ₹12,000 less than A, what was A’s investment (principal)?
Show answer & explanation
Correct answer: C
Explanation
Given:
Interest rate = 5% per annum
A's time = 4 years
B's time = 6 years
B's investment = ₹12,000 less than A's
Formula:
Simple interest = PRT / 100
Let A's investment = x
B's investment = x − 12,000
A's simple interest = x × 5 × 4 / 100 = x/5
B's simple interest = (x − 12,000) × 5 × 6 / 100
= 3(x − 12,000)/10
Both are equal
x/5 = 3(x − 12,000)/10
2x = 3x − 36,000
x = 36,000
A's investment = ₹36,000.