Question

A large watermelon weighs 20kg with 96% of its weight being water. It is allowed to stand in the sun and some of the water evaporates, so that now only 95% of its weight is water. Its reduced weight will be
A) 18kg
B) 17kg
C) 16.5kg
D) 16kg

Answer 1

Hint: in order to solve the question, we have given that a large watermelon weighs 20kg with 96% of its weight being water. From this information, we will find out the weight of the water and pulp in the given net weight of water melon. Then we are given that watermelon is placed in the sun and some of the water evaporates, and as we know that, the weight of the water melon is reduced because only water evaporates the weight of the watermelon pulp remains the same. So will equation now the new weight of water melon pulp to the previous weight we found in this way we will get the reduced weight of the water melon.

Complete step-by-step solution:
We have given that, A large watermelon weighs 20kg with 96% of its weight being water.
Thus, Weight of the water in 20kg of watermelon = \[\dfrac{96}{100}\times 20=19.2kg\]
So, there is 19.2kg of water in 20kg of watermelon.
So, Weight of the watermelon pulp = \[20kg-19.2kg=0.8kg=800grams\]
Now,
We have been given that watermelon is allowed to stand in the sun and some of the water evaporates, so that now only 95% of its weight is water.
Now,
Let the reduced weight of watermelon be ‘x’.
So,
Weight of the water = 95% of ‘x’
Weight of the watermelon pulp $ = 100% - 95% = 5% of ‘x’$
As we know, the weight of the water melon is reduced because only water evaporates and the weight of the watermelon pulp remains the same.
Thus,
Weight of the water melon pulp = 5% of ‘x’ = 0.8kg
So, \[\dfrac{5}{100}\times x=0.8\Rightarrow x=0.8\times \dfrac{100}{5}=16kg\]
Thus, the reduced weight of the water melon is 16kg.
Hence, the option (D) is the correct answer.

Note: While solving the question, the key note to solve this question is that when the watermelon is allowed to stand in the sun and some of the water evaporates, then the weight of the water melon reduced only because water evaporates and only the quantity of water reduced and the weight of the watermelon pulp remain same.