William and Stephanie are painting the bedrooms in their house. If he had to paint the bedrooms himself, it would take William four hours to complete the job. If Stephanie alone were to paint the bedrooms, it would take her six hours.Working together, how long will it take William and Stephanie to paint the bedrooms?
Mathematics · College · Thu Feb 04 2021
Answered on
first, you have to finding the rate of per hour at which Sally and John can paint
If Sally can paint the entire house in 4 hours, then she can paint 1/4 of the house in 1 hour and If John can paint the entire house in 6 hours, then he can paint 1/6 of the house in 1 hour.
Together, they can paint :-1/4 + 1/6 = 3/12 + 2/12
= 5/12 (together paint house in 1 hour)
let H = total house paint
(5/12)H = 1 hour.
To find 1 H, you would multiply both sides by the multiplicative inverse of 5/12, that's 12/5.
H = 12/5 hours
So, together they can paint the entire house in 12/5 hrs. = 2.4 hrs.
=2 hours 40 minutes.