Answer:
288
Explanation:
First, find how much of the desk each person can finish in 1 hour. Paul can finish 1/12 because he finishes the whole thing in 12 hours and Shawn can finish 1/8 because he finishes the whole thing in 8 hours.
Then find a common denominator and add those together to find how much they could do together in 1 hour.
2/24 + 3/24 = 5/24 So they can finish 5/24 of the desk in 1 hour if they work together.
So to finish 24/24 of the desk, they'll need to do 4 hours (20/24 of the desk) and 48 minutes (4/24 of the desk)
It asked for the number of minutes, so multiply 4 by 60 and add 48 to find the total number of minutes. 4*60 = 240 and 240 + 48 = 288
So it will take them 288 minutes to build the desk together.