Time Word-Problem (how long to paint the house together?)

[Guest]

How would you guys answer this word-problem?

If Sally can paint a house in 4 hours, and John can paint the same house in 6 hour, how long will it take for both of them to paint the house together?

I don't know what the procedure is to answer this word-problem. Can somebody please show me how to get the answer? Thanks!

 

[galactus]

How much of the house can Sally paint in 1 hour?......1/4

How much of the house can John paint in 1 hour?......1/6


Together?......1/t


\(\displaystyle \L\\\frac{1}{4}+\frac{1}{6}=\frac{1}{t}\)

Solve for t.

 

[Guest]

It says the answer is 2 hours and 24 minutes when i checked the answer....how did this happen?

 

[galactus]

It says the answer is 2 hours and 24 minutes when i checked the answer....how did this happen?

12/5=2.4 hours

2 + (.4)(60)= 2 hours and 24 minutes.

 

[Denis]

angelika, you were told equation was: 1/4 + 1/6 = 1/t and to solve that for t.

you don't know how to do that? what grade are you in?
what happens if you multiply each of the 3 terms by 12?