Question

sam is twice as efficient plumber as joe and togheter they finish a work in 8 days. in how many days can it done by sam alone

Answer 1

Solution :-

As per the question Sam is twice as efficient plumber as Joe. 

So, Sam : Joe = 2 : 1

Now, Sam and Joe work together and finish a work in 8 days. 

So, 1 day work of Sam and Joe when they work together = 1/8

To find the number of days in which Sam will finish the work alone, let us calculate work done by Sam in 1 day = (1/8 × 2/3)

= 2/24  

= 1/12th part of the whole work.

So, Sam will finish the whole work in 12 days.

Answer.

Answer 2

Sam and Joe work together in 8 days 
SAM is twice as efficient as compared to Joe.
So if both were equally efficient then they must need 8 days each to complete the work. but in the given situation since Sam is twice as efficient as compared to Joe then he must be doing 75% of work and and Joe must be doing 25% of work if both were doing equal work then they would need 8 days but in this case only 12 days must be required by Sam