If a sum on compound interest becomes three times in 4 years, then with the same interest rate, the ...
If a sum on compound interest becomes three times in 4 years, then with the same interest rate, the sum will become 81 times in:
Answer/Solution
16 years
Steps/Work
Explanation:
The sum P becomes 3P in 4 years on compound interest
3P = P(1+R/100)4
⇒ 3 = (1+R/100)4
Let the sum P becomes 81P in n years
81P = P(1+R/100)n
⇒ 81 = (1+R/100)n
⇒ (3)4 = (1+R/100)n
⇒ ((1+R/100)4)4 = (1+R/100)n
⇒ (1+R/100)16 = (1+R/100)n
n=16
i.e, the sum will become 81 times in 16 years
ANSWER IS C
The sum P becomes 3P in 4 years on compound interest
3P = P(1+R/100)4
⇒ 3 = (1+R/100)4
Let the sum P becomes 81P in n years
81P = P(1+R/100)n
⇒ 81 = (1+R/100)n
⇒ (3)4 = (1+R/100)n
⇒ ((1+R/100)4)4 = (1+R/100)n
⇒ (1+R/100)16 = (1+R/100)n
n=16
i.e, the sum will become 81 times in 16 years
ANSWER IS C