Question

Q. Thomas invested a sum of money at simple interest which triples itself in 8 years. In how many years will it become 8 times itself at the same rate?

• A. 21 years
• B. 24 years
• C. 28 years
• D. 30 years

Answer 1

The correct option is C 28 years

For principal amount x
Interest generated in 8 years is 2x
For rate of interest R
$2x=x\times 8\times \frac{R}{100}R=\frac{200}{8}=25\%$
For interest = 7x
Time = T
$7x=x\times \frac{25}{100}\times TT=\frac{700}{25}=28$ years