Seth does x oil changes in 8 hours and Max does x oil changes in 6 hours. They together did 35 oil changes in 8 hours how many did each of them do individuality

Question

I am asking this question for a friend and would like an answer asap

Answer 1

Hello Matthew and friend,

 

Step one is to figure out how much of the oil change each person does in one hour.

 

If you can do 2 oil changes in 6 hours, then you can do 2/6 of an oil change in one hour.

 

So Seth does X/8 oil changes in 1 hour and Max does X/6 oil changes in one hour.

 

Together they did 35/8 oil changes in one hour.

 

So, X/8 + X/6 = 35/8

 

Using 24 as a common denominator--> 3X/24 + 4X/24 = 35/8

 

7X/24 = 35/8

 

Cross multiply--> 56X = 840

 

Divide both sides by 56--> X = 15

 

That means that Seth did 15 oil changes in 8 hours.  Then Max must have done 35 - 15 = 20 oil changes in 8 hours. 

 

Seth is slow.

 

Dan