Answer:
1800 sq ft.
Step-by-step explanation:
Let x represent the amount of space in the garage.
We know that he is estimating 6 sq ft per person, for 15 people; this gives us
6(15) = 90 sq ft.
This is 5% of the total, x; 5% = 5/100 = 0.05; this gives us 0.05x.
Together these give us the equation
0.05x = 90
Divide both sides by 0.05:
0.05x/0.05 = 90/0.05
x = 1800