Question

For a fixed amount, when the rate of interest is doubled and the time becomes 5 times, the interest becomes

• A. $10times$
• B. double
• C. treble
• D. $4times$

Answer 1

The correct option is A

$10times$

$$\begin{gathered} S{I}_1=\frac{P\times R\times T}{100} \\ Whenratebecomesdoubleandtimebecomes5times, \\ S{I}_2=\frac{P\times 2R\times 5T}{100} \\ \frac{S{I}_1}{S{I}_2}=\frac{P\times R\times T/100}{P\times 2R\times 5T/100}=\frac{1}{10} \\ S{I}_1=10S{I}_2 \\ Thus,SIbecomes10times. \end{gathered}$$