Answer:
2/3
Step-by-step explanation:
We are told in the question that
If one quart of paint is exactly enough for two coats of paint on a 9-foot by 10-foot wall
9 foot by 10 foot wall = an area of 9 × 10 = 90ft² × 2 coats of paint = 1 quart of paint
We are to find how many quarts of paint are needed
how many quarts of paint are needed to apply one coat of paint to a 10-foot by 12-foot wall .
10 × 12 = 120ft² × 1 coat of paint = x quart
Mathematically, if
One quart of paint = 90ft² × 2
x quart of paint = 120ft² × 1
Cross multiply
90ft²× 2 × x = 120ft²
x = 120/180
x = 2/3 quart of paint
