Question

Jordan can build a birdhouse in 2 hours. If it takes her sister 3 hours to build a birdhouse, how long will it take them to build a birdhouse together?

Answer 1

To find the total work of two people at different speeds, we need to find a common speed limit to both.

In this case, Jordan can build a birdhouse in 2 hours so her speed is 1/2 birdhouse per hour.

For the sister, it takes 3 hours to build a birdhouse so her speed is 1/3 birdhouse per hour.

To find what they can do in one hour: $\frac{1}{3} + \frac {1}{2} = \frac{2}{6} + \frac{3}{6} = \frac{5}{6}$

To find how long does it take to build a birdhouse: $\frac{ \frac{5}{6}}{1} = \frac{1}{x}$

Set the denominators equal: $\frac{\frac{5}{6}x}{x} = \frac{1}{x}$

Remove the denominators and solve: $\frac{5x}{6} = 1$

Once again set the denominators equal: $\frac{5x}{6} = \frac{6}{6}$

Remove the denominators and solve for x: $5x = 6 \\ \\ x = \frac{6}{5}$

6/5 hours is equal to 72 minutes.

Answer 2

Answer:

if you came on here to find the answer for the A-Beka Algebra 1 quiz 36 for this question the answer is 1 1/5hr. or 1hr.12min.

Step-by-step explanation:

1. B. Cross multiply

2. D. 1

3. B. proportion

4. A. 4a-2/8a-a^2

5. a=2

6. c=0,6

7. 150ft (or just) 150

8. 1 1/5hr. (OR) 1hr.12min.