Question

A sum of money becomes six times at the simple interest rate of $5\%$ per annum. At what rate per cent will it become twelve fold? [The time period is unaltered.]

• A. $10\%$
• B. $12\%$
• C. $9\%$
• D. $11\%$

Answer 1

Answer: (D)

$11\%$

Given : Amount $=6P$ , $R=5$% Time $=T$

$SI+P=6P$

$SI=5P$

$SI=\frac{PRT}{100}\Rightarrow 5P=\frac{P\times 5\times T}{100}\Rightarrow T=100$

Given time is same, Amount $=12P$

$SI=12P-P=11P$

$\Rightarrow \frac{PRT}{100}=11P\Rightarrow R=\frac{11\times 100}{100}=11$

Hence, the correct answer is $11\%$.