Question

Frances can complete 91oil changes in 7 days. How many oil changes can Frances complete in 11days? oil changes

Answer 1

143 oil changes

Explanation:

Let's find out Frances' rate per 1 day. We can set up a proportion, since we know he can do 91 oil changes in 7 days:

`(91)/(7) =(x)/(1)`, where x is the number of oil changes Frances can do in 1 day

Cross-multiply:

91 * 1 = 7 * x

7x = 91

x = 91/7 = 13

So Frances can do 13 oil changes in 1 day. Set up another proportion to find how many oil changes he can complete in 11 days:

`(13)/(1) =(y)/(11)`, where y is the number of oil changes Frances can do in 11 days

Cross-multiply:

13 * 11 = 1 * y

y = 143

The answer is 143 oil changes.

Hope this helps!

Answer 2

143

Explanation:

lets make a fraction:

so

91 oil changes/7days

lets take "x" as the unknown # of oil changes:

so

x/11

91/7=x/11

we can cross multiply:

91*11=7*x

1001=7x

143=x

so 143 oil changes in 11 days

Hope this helps!