Find the time for two people working together to complete half a task if it takes them 8 hours and 10 hours to complete the entire task working individually.

2 answers

rate of worker 1 = job/8
rate of worker 2 = job/10

their combined rate = job/8 + job/10
= (4job + 5job)/140 = 9job/40

so the time is job/(9job/40) = 4.44 hours
or 4 hours and 27 minutes

(job canceled in the division of fractions above)
Thank you so much Reiny=:)