Question

Write an equation that can be used to solve the problem. Then answer the question asked. A group of college students are volunteering for Habitat for Humanity during their spring break. They are putting the finishing touches on a house they built. Working alone, Dale Horton can paint a certain room in 3 hours. Kathy Garcia can paint the same room in 9 hours. How long will it take them working together to paint the room?

Answer 1

Answer:

Required equation : $\frac{1}{t}=\frac{1}{3}+\frac{1}{9}$

Together they can paint the same room in 2.25 hours or 2 hours 15 minutes.

Step-by-step explanation:

It is given that Dale Horton can paint a certain room in 3 hours.

One hour woks of Dale Horton = 1/3

Kathy Garcia can paint the same room in 9 hours.

One hour woks of Kathy Garcia = 1/9

Let together they can paint the same room in t hours.

One hour woks of both = 1/t

$\frac{1}{t}=\frac{1}{3}+\frac{1}{9}$

$\frac{1}{t}=\frac{3+1}{9}$

$\frac{1}{t}=\frac{4}{9}$

After reciprocal we get

$\frac{t}{1}=\frac{9}{4}$

$t=2.25$

1 hour = 60 minutes.

0.25 hour = 15 minutes.

Therefore, together they can paint the same room in 2.25 hours or 2 hours 15 minutes.