The word questions of the rational function

Question

Palmer’s crew can do the cement work for a new building in 6 days. Hoffman’s crew would need 8 days to

complete the same job. How many days will the job take if the two crews work together?

Let x be the number of days it will take if the crews work together.

Answer 1

1/x = 1/6 + 1/8

24 = 4x +3x

x = 24/7 = 3 3/7 hours working together

check with a rough approximation

they average each alone 7(6+8)/2 = 7 hours

half 7 = 3.5 which is close to 3 3/7