33.9k views
0 votes
If one quart of paint is exactly enough for two coats of paint on a 9-foot by 10-foot wall, how many quarts of paint are needed to apply one coat of paint to a 10-foot by 12-foot wall? Express your answer as a common fraction

User Jim Rhodes
by
5.7k points

2 Answers

6 votes

Answer:

2/3 of a quart

Explanation:

2 coats on a 9X10=1 coat on a 18X10. Since 18X10 is 1.5 times 12X10, the 12X10 will need 2/3 of the paint

User Rory MacLeod
by
4.7k points
4 votes

Answer:

2/3 quart

Explanation:

The 10 by 12 ft wall has an area of 120 ft^2. The 9 by 10 ft wall has an area of 90 ft^2.

Thus, the following equation of ratios provides us with the answer:

90 (1/2)

--------- = -----------

120 x

or 3/4 = 1/(2x), or

6x = 4. Thus, x = 4/6 or 2/3.

2/3 of a quart would be enough for one coat on the 10 by 12 ft wall. Note that only 1/2 of a quart would suffice for one coat on a 9 by 10 ft wall (for comparison).

User LightStruk
by
5.3k points