Question

Mohit can do piece of work in 8 hours. jim can do it in 10 hours and Jack can do it in 20 hours . In how much time will they all complete the work together.
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Answer 1

Answer:

6hrs 40 min

Step-by-step explanation:

Ravi's 1 hour's work = 1/15 &

Raman's 1 hour's work =1/12

Both's 1 hour's work = 1/15+1/12 =9/60

let both take to do it in t hours

(9/60)t =1

t = 60/9h = 6h + (6×60)/9min

t = 6hour and 40 minute