Test Index

AFCAT Model Paper 10

Question : 63 of 100

Marks: +1, -0

Solution:

Given:

Ratio of difference between CI and SI for 3 years and 2 years respectively = 25: 8

Formula used:

Difference between CI and SI for 3 years

=\frac{PR^{2}(R+300)}{100^{3}}

Difference between CI and SI for 2 years

=\frac{PR^{2}}{100^{2}}

Calculation:

According to question:

\frac{ \left[ \frac{PR^{2}(R+300)}{100^{3}} \right] }{ \left[ \frac{PR^{2}}{100^{2}} \right] } = \frac{25}{8}

Solving LHS:

\Rightarrow \frac{R+300}{100^{3}} \times 100^{2}

\Rightarrow \frac{R+300}{100} = \frac{R}{100} + 3

R\% + 3

Now, R%

+ 3 = \frac{25}{8}

⇒ R%

= \left( \frac{25}{8} \right) - 3 = \frac{1}{8}

∴ Rate of interest $= \frac{1}{8} = 12.5\%$

Go to Question:

Prev Question

Next Question