If a sum of money becomes ₹6,000 in 3 years and ₹10,500 in 7 years and 6 months at the same rate of simple interest, then what is the rate of interest?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. %.
Interest earned in 4 years and 6 months = 10500 - 6000 = ₹4500
Interest earned for 1 year = 4500/4.5 = ₹1000
Interest earned for 3 years = 1000 × 3 = ₹3000
So,
Principal = 6000 - 3000 = ₹3000
Now,
⇒ S.I. = (P × R × T)/100
here, S.I. = Simple Interest, P = principal, R = Rate, and T = Time
⇒ 3000 = (3000 × R × 3)/100
⇒ R = 100/3 = %