A large watermelon weighs 20 kg with 96\% of its weight being water. It is allowed to stand in the sun and some of the water evaporates so that only 95\% of its weight is water. Its reduced weight will be
(a)16 kg
(b)16.5 kg
(c)17 kg
(d)18 kg
Answer
Answer (as printed): A
Explanation
Let the reduced weight be $x \mathrm{kg}$. Clearly, the quantity of pulp remains the same in both the cases. So, $(100-96) \%$ of $20 \mathrm{kg}=(100-95) \%$ of $x \mathrm{kg}$ $$\Leftrightarrow 4 \% \text { of } 20 \mathrm{kg}=5 \% \text { of } x \mathrm{kg} \Rightarrow x=\left(\frac{4}{5} \times 20\right) \mathrm{kg}=16 \mathrm{kg} .$$