Question

Karthik is n years old today, 10 years ago his age was half of the present age. Find n.
A.20
B.24
C.25
D.18

Answer 1

Hint: We have given the present age of Karthik i.e. n, and have given a statement that 10 years ago his age was half of the present age. Using this we will create an equation in ‘n’, on solving that equation we will get the value of ‘n’ hence will get the present age of Karthik.

Complete step-by-step answer:
Given data: Present age of Karthik( in years) $ = n$
10 years ago his age was half of the present age
It is given that the present age of Karthik in years $ = n$
10 years ago, the age of Karthik in years $ = \dfrac{n}{2}$
Since it is given that 10 years ago his age was half of the present age
$ \Rightarrow n - 10 = \dfrac{n}{2}$
Multiplying both sides by 2
$ \Rightarrow 2n - 20 = n$
On simplifying for like terms, we get,
$ \Rightarrow 2n - n = 20$
$\therefore n = 20$
Therefore the Present age of Karthik( in years) $ = 20$
Hence, option(A) is correct.

Note: While writing the age of the person 10 years ago most of the students write it as 10 years which in this case will give the same answer but the process is not correct as 10 years ago his age was (n-10) years. So remember to execute every point correctly to get the correct answer as well as with the accurate method.