Question

It took 4 hours to clean 10 houses, how many houses could be cleaned in 8 hours?

Answer 1

3 1/2 houses

Explanation:

To find the unit rate we must divide 4 by 10

4 hours divided by 10 house = 1/4

1/4 houses per hour

8 hours times 0.4= 3.2 houses

Answer 2

20 houses

Explanation:

Let’s make a proportion using this setup:

houses/hours=houses/hour

We know that 10 houses can be cleaned in 4 hours. We don’t know how many houses can be cleaned in 8 hours, so we can say x houses can be cleaned in 8 hours.

10 houses/4 hours= x houses/8 hours

10/4=x/8

Now we have to solve for x, by getting x by itself. Perform the opposite of what is being done to both sides.

x is being divided by 8. The opposite of division is multiplication, so multiply both sides by 8

8(10/4)=(x/8)8

8(10/4)=x

8(2.5)=x

20=x

20 houses can be cleaned in 8 hours.