Question

Govind weighs 15 kg more than Govil. If Govil weighs $\dfrac{3}{4}$ as much as Govind; find their weights:
(A) Govind $ = 20kg$ and Govil $ = 45kg$
(B) Govind $ = 90kg$ and Govil $ = 45kg$
(C) Govind $ = 30kg$ and Govil $ = 45kg$
(D) Govind $ = 60kg$ and Govil $ = 45kg$

Answer 1

Hint: Assume the weight of any one of them some variable and then form a linear equation in one variable using the condition given in the question. Solve the equation to find out their weights. Their weights are related so we need to solve only one equation.

Complete Step-by-Step solution:
According to the question, Govind weighs 15 kg more than Govil.
Let the weight of Govil is x kg. Then the weight of Govind is $\left( {x + 15} \right)$ kg.
Further it is given that the weight of Govil is $\dfrac{3}{4}{\text{th}}$ of the weight of Govind. So, we have:
$ \Rightarrow x = \dfrac{3}{4} \times \left( {x + 15} \right)$
Solving this equation for x, we’ll get:
$
   \Rightarrow 4x = 3x + 3 \times 15 \\
   \Rightarrow x = 45 \\
$
Thus, the value of x is 45. So we have:
$ \Rightarrow \left( {x + 15} \right) = 60$
Thus, the weight of Govind is 60 kg and the weight of Govil is 45 kg. (D) is the correct option.

Note: We can also solve the question by using options, without forming any equation. As we can see that last option is the only one in which Govind weighs 15 kg more than Govil. Or if we have to solve the question using an equation, we can still verify our answer using the option elimination method.