On simple interest, a certain sum becomes Rs.59,200 in 6 years and Rs.72,000 in 10 years. If the rate of interest had been 2% more, then in how many years would the sum have become Rs.76000?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 9
On Simple Interest, the sum becomes 59200 in 6 years and 72000 in 10 years
Thus, the interest in 4 years = 72000 - 59200 = 12800
And, the interest for 1 year = 12800/4 = 3200
And, the interest in 6 years = (12800/4) × 6 = 19200
The Principal will be 59200 - 19200 = 40000
If the interest rate had been 2% more = 40000 × (2/100) = 800
Thus, interest for 1 year would have been 800 more
Thus, interest in 1 year would be 4000
It would take (76000 - 40000)/4000 years to have an amount of 76000 on the principal of 40000
⇒ (76000 - 40000)/4000 = 36000/4000 = 9 years