To solve this question we have to make deduct these 2 years. 2100 minus 1985 will give the answer.
You are 115 years old.
(1380 months are passed.)
From 1985 to 2100 there are 115 years. If you want to learn your age in 2100 (born in 1985) your age is 115.
Let's see what will be your age if you born +1 or -1 from that date.