Q4 of 47 Page 172

Two motor mechanics, Raju and Siraj, working together can overhaul a scooter in 6 hours. Raju alone can do the job in 15 hours. In how many hours can Siraj alone do it?

Number of hours Raju required to overhaul a scooter : 15 hours


Let number of hours siraj required to overhaul a scooter : X hours


Number of hours required by Raju and Siraj together to do a piece of work : 6 hours


Work done by Raju in one hour:


Work done by Siraj in one hour:


Work done by Raju and Siraj together in a one hour :


Work done by Raju and Siraj together in one hour : = =



⇒ 6X +90 = 15X


⇒ 9X = 90


⇒ X = = 10 hours


Siraj can do the work 10 hours.


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