Math word problem

Question

Together rick and john can carpet a room in 12 hours. Working alone rick can carpet the room in 7 hours less time than john. How long will it take rick to carpet the room how long will it take john?

 

Thanks in advance!

Answer 1

Hi Stephanie!

 

I tell my students to take word problems like this and write them in Math-ese...that's math language.

 

Let R be the number of hours it takes Rick to carpet the room. 

Let J be the number of hours it takes John to carpet the room.

 

Then in math language you could say:

 

R+J = 12

 

Since it takes Rick 7 hours less than John couldn't you say:

 

R = J-7  ?

 

Then you have an expression for R in terms of J and you can subsitute it back into the original equation.

 

(J-7) + J = 12

2J -7 = 12

2J=19

J = 9.5  so it takes John 9.5 hours to carpet the room

 

Since it takes Rick 7 less hours you have: R = 9.5-7 = 2.5 hours to carpet the room

 

Hope this helps.