A sum at simple interest becomes two times in 8 years at a certain rate of interest p.a. The time in which the same sum will be 4 times at the same rate of interest at simple interest is:
Answer & explanation
Correct answer: option 3
A sum at simple interest becomes two times in 8 years at a certain rate of interest p.a.
Let principal = P
So , Amount = 2p in 8 years
SI = Amount - Principal
= 2P - P
= P
We know ,
Simple Interest = \(\frac{Principal ×Rate × Time }{100}\)
P = \(\frac{P×Rate × 8 }{100}\)
Rate = 12.5%
Now, Required amount is 4 times of Initial Sum.
3P = \(\frac{P× 12.5 ×Time }{100}\)
Time = 24 years