Question

Carl can paint a room 3 hours faster than Jennifer can. If they work together, they can complete the job in 2 hours. How long does it take Jennifer to complete this job on her own?

Answer 1

Why would you multiply the first rate by 3?

Answer 2

typo!

Here is the corrected version
et Jennifer paint 1 room in T hours. Her rate is 1 room/T hours or 1/T rooms per hour

Carl does 1 room in T-3 hours, so his rate is 1/(T-3)

now use rate * time = 1 room
in 2 hours they finish a room together:

\[ \frac{1}{T}\cdot 2 + \frac{1}{T-3}\cdot 2 = 1 \]
now solve for T to find how long it takes for Jennifer to paint a room