Question

Deepak is twice as old as his brother Vikas. If the difference of their age is 11 years. Find their present age.

Answer 1

Hint: Now first let us assume the age of Deepak to be x and the age of Vikas to be y. Now we are given that Deepak is twice as old as his brother Vikas. Hence using this we get our first equation. Now we also know that the difference of their age is 11 years. Hence we get our second equation. Now we will solve the equation simultaneously to find the values of x and y respectively.

Complete step by step answer:
Now let us say that the age of Deepak is x and the age of Vikas is y.
Now we are given that Deepak is twice as old as his brother Vikas.
Hence we can say that x = 2y.
Now rearranging the terms of the equation we get, x – 2y = 0 ………………….. (1)
Now we also have the difference of their age being 11 years.
Hence we can say that x – y = 11.
Now multiplying the above equation by – 2 we get, –2x + 2y = – 22 …………..(2)
Now let us add equation (1) and equation (2) we get,
x – 2x = – 22
Hence we get – x = - 22. Which means x = 22.
Now let us substitute the value of x in equation (1).
Hence we have 22 = 2y.
Dividing the whole equation by 2 we get,
11 = y.

Hence we finally get x = 22 and y = 11.

Note: Now here we are given that the difference of their age is 11 years. But from the first condition we have Deepak is twice as old as his brother Vikas. Hence we know that Deepak is older than Vikas. Hence while taking the subtraction we consider x – y and not y – x.