To solve this question we have to make deduct these 2 years. 2120 minus 1975 will give the answer.
You are 145 years old.
(1740 months are passed.)
From 1975 to 2120 there are 145 years. If you want to learn your age in 2120 (born in 1975) your age is 145.
Let's see what will be your age if you born +1 or -1 from that date.