Question

A boy is given rich diet and gains 15% in weight. He is then put on a poor diet and loses 20% in weight. On the whole the boy will

• A. lose 5% weight
• B. lose 10% weight
• C. lose 8% weight
• D. remain the same

Answer 1

Answer: (C)

$\Rightarrow$ Let original weight of boy be $100$.

$\Rightarrow$ Weight of boy after rich diet = $100+\frac{15}{100}\times 100=115$

$\Rightarrow$ Then, after poor diet boy loses weight 20%.

$\therefore$ Weight of boy after poor diet = $115-115\times \frac{20}{100}=92$

$\Rightarrow$ Loss weight % = $\frac{100-92}{100}\times 100=8\%$