Yes, if that is the expenses he has to pay for all three of them. All you have to do is add up the all his expenses and multiple by 12
40% = 0.4
Explication:
40 / 100 = 0.4
It subtracts 1 then 2 then 3
The opposite of a number is its negated value. So, if you negate 0.2, you get -0.2.
