A sum amounts to Rs 1326 in 6 years at 5% p.a. simple interest. In what time will this sum double itself at the same rate of interest?

Asked by bubu64272 | 30th Dec, 2018, 10:50: PM

Expert Answer:

Let the sum be Rs. x.
A = Rs. 1326, n = 6 years, r = 5% p.a. 
 
A = P + SI
1326 = x + x × 6 × 5/100
x + 0.3x = 1326
1.3x = 1326
x = 1020
Hence, the sum invested is Rs. 1020.
According to the question,
P = Rs. 1020 and A = Rs. 2 × 1020 = Rs. 2040
A = P + SI
2040 = 1020 + 1020 × n × 5/100
We get n = 20 years
 
In 20 years time the sum will be double at the same rate of interest.

Answered by Sneha shidid | 31st Dec, 2018, 09:57: AM