P, Q, R can do a piece of work in 70, 84, 280 hours respectively. If they work together, how many hours will they take?
P, Q, R can do a piece of work in 70, 84, 280 hours respectively. If they work together, how many hours will they take?
Option 1 -
34 hours and 24 minutes
Option 2 -
33 hours and 36 minutes
Option 3 -
33 hours and 30 minutes
Option 4 -
34 hours and 36 minutes
Asked by Shiksha User
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1 Answer
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Correct Option - 2
Detailed Solution:LCM of 70, 84, 280 is 840.
Let total work = 840 units.
Per hour work of P =
Per hour work of Q =
Per hour work of R =
Number of hours they require together =
= 33 hours and 36 minutes
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