NIMCET 2020 — Reasoning PYQ

Let the age of the person's mother be‘a’units.

So,  age of the person= ( 2/ 5) a

After 8 years,  age of the perso$n^{\prime }$s mother= ` a+ 8 units

So age of the person after 8 years = (a+8)/2

According to question:

(2/5)a+8=(a+8)/2

=>(2\mathrm{a}+40)/5=(\mathrm{a}+8)/2

=>4a+80=5a+40

=>a=40

So, the present age of his mother is 40 years.
Hence, '40 vears'is the correct answer.