Question

X is 36 years old and Y is 16 years old. In how many years will X be twice as old as Y?
A. $1year$
B. $2years$
C. $3years$
D. $4years$

Answer 1

Hint: In the question, we are given the ages of X and Y. we need to calculate the number of years after which X will be twice as old as Y. We will take the ages of X and Y after $x$ years. Now, we will calculate the age of X and Y after $x$ years. Let x be the number of years when X will be twice as old as Y. Now, we will equal the ages of X and Y. Thus we will find the value of $x$.

Complete step-by-step solution:
In the above question, we have to find that after how many years will X be twice as old Y.
Now, $x$ will be the number of years after which the age of X will be twice as old as Y.
So, the age of X and Y after $x$ years will be
$ \Rightarrow {X_{age}} = \left( {36 + x} \right)yrs$
$ \Rightarrow {Y_{age}} = \left( {16 + y} \right)yrs$
Now, we know that X’s age will be twice of Y’s after $x$ years
So,
$
   \Rightarrow 36 + x = 2\left( {16 + x} \right) \\
   \Rightarrow 36 + x = 32 + 2x \\
   \Rightarrow x = 4
 $
Thus, after 4 years the age of X will be twice as old as Y.

Hence, the correct option for this question is D.

Note: In these types of questions, try not to get tricked. Try to analyze the data given precisely. Now, we have sold this question by forming linear equations and then comparing them to get the value of the variable. These types of questions can be easily solved by making equations of the given data.
Most importantly in these types of questions, always verify your solution by putting the answer in the equations.