Question

Find a single discount equivalent to the successive discounts of $10\%,20\%$ and $20\%$ (in percent).

• A. $42.1\%$
• B. $42.4\%$
• C. $42.8\%$
• D. $45\%$

Answer 1

The correct option is B $42.4\%$

$\Rightarrow$ Single equivalent discount for successive discount of $10\%$ and $20\%$.

$\Rightarrow$ $[10+20-\frac{20\times 10}{100}]\%=28\%$

$\Rightarrow$ Single equivalent discount for $28\%$ and $20\%$

$\Rightarrow$ $[28+20-\frac{28\times 20}{100}]\%=42.4\%$