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Question

Question:

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?

Possible Answers:
2 hours and 24 minutes
3 hours and 12 minutes
3 hours and 44 minutes
4 hours and 10 minutes
4 hours and 33 minutes

Thankyou

Answer 1

t/6 +t/4=1
so 4t+6t=24
10t=24
t=2.4hours or 2hours and 24 minutes

Answer 2

To break this problem down, try to think of it this way:
For Sally, 1 house = 4 hours. If Sally has 2 hours, she can paint 1/2 of a house. In 1 hour, Sally can paint 1/4 of a house. Apply that same thinking to John, and you'll see that in 1 hour, John can paint 1/6 of a house.

If they work together for 1 hour, then they paint (1/4+1/6) of a house. 1/4 + 1/6 = 5/12, so they can paint 5/12 of a house in 1 hour.

Write that last statement out as an equation:
5/12 house = 1 hour

What you want to get is how many hours it takes for 1 house, so multiply both sides by 12/5 so that you get an equation where you have 1 house:

1 house = 12/5 hours

So, 1 house takes the both of them together 2.4 hours.

Answer 3

I'm terribly sorry, I can't seem to figure this out. I'm thinking something along the lines of finding the difference or something. Good luck with this question

Answer 4

Hmm...What grade level is this?