If the two work​ together, find how long it takes them to complete the job.

Question

A company found that an experienced surveyor can survey a roadbed in 7 hours. An apprentice surveyor needs

9 hours to survey the same stretch of road. If the two work​ together, find how long it takes them to complete the job.

Answer 1

1/9 + 1/7 = 1/x

multiply by 63x

7x + 9x = 63

16x = 63

x = 63/16 = about 3.9 hours

They're averaging about 8 hours each

together should do half that or abour 4 hours