To solve this question we have to make deduct these 2 years. 2020 minus 2015 will give the answer.
You are 5 years old.
(60 months are passed.)
From 2015 to 2020 there are 5 years. If you want to learn your age in 2020 (born in 2015) your age is 5.
Let's see what will be your age if you born +1 or -1 from that date.