If you earn $1200 per month and you expect your earnings to increase by 10% per year, what monthly salary would you be making in 5 years?

So u turn the percent into a decimal.
0.10 
Now multiply 1200 * 0.10
1200*0.10= 120 ( 120 is the amount that is gonna increase)
So if it says 5 years, than your gonna multiply 120 * 5 
120*5 =600
So your gonna add 600 to 1200.
So in five years your gonna be making 1,800.
An easier way would be to use prt
Principle * rate * time
1200 * 0.10* 5
= 600
So now you just add 600 to 1200
= 1800