Answer:
It will take them 8 minutes to work together
Explanation:
Trent: 10 minutes = 1/10
Lois: 40 minutes = 1/40
Together: x minutes = 1/x
1/10(10x) + 1/40(10x) = 1/x(10x) --> x + 1/4x = 10 --> 5/4x = 10
10/1 divided by 5/4x = 10 times 4 divided by 5 = 8 minutes