Question

james can do a piece of work in 14 days and peter in 21 days. they begin together. but after 7 days before the completionof the work james leaves off. in how many days is the work completed za?

Answer 1

Q. james can do a piece of work in 14 days and peter in 21 days. they begin together. but after 7 days before the completionof the work james leaves off. in how many days is the work completed za?

Solution :-

James can do the work in 14 days.

Work Rate of James = 100/14 = 7.14%  per day

Partner can complete the work in 21 days.

Work rate of Partner = 100/21 = 4.76% per day.
Work rate,

James + Partner =  7.14 + 4.76 = 11.90 per day

They together can finish work in,
= 100/11.90 = 8.4

They Work together for = 8.4 - 7 = 1.7 days.

So, if they work together then, they can complete work in 7 days

11.90×7 = 83.3%

83.3% of the work completed by Partner alone in,
= 83.3 / 4.76= 18.67 days.

Total Time taken to finish the wor,
= 18.67 + 1.7 = 20.37 days (Approx.)

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