A and B can do a piece of work in 15 days. B and C can do the same work in 10 days and A and C can do the same work in 12 days. Time taken by A, B and C together to do the job is? A और B 15 दिनों में एक काम कर सकते हैं। B और C एक ही काम को 10 दिन और A और C एक ही काम को 12 दिनों में कर सकता है। काम करने के लिए A, B और C द्वारा एक साथ लिया गया समय है?
Answers
Answer:
LCM(12,15,20)=60
Now this 60 units can be treated as the total work and we will now calculate the one day work
One day work of A and B = 60/12 = 5 units
One day work of B and C = 60/15 = 4 units
One day work of C and A = 60/20= 3 units
Now if we add all three we get:-
2(A+B+C)=12 units
So one day work of A, B and C put together is 12/2 = 6 units
To find one day work of A:-
One day work of A, B and C together minus one day work of B and C, that is 6–4=2 units
If the total work is of 60 units and the one day work of A is 2 unit, then alone A needs 60/2 = 30 days to finish the work.
The same way we can find the number of days required by B and C to finish the work by themselves.
Believe me, every question on time and work can be solved with this method and it's really a time saver in exams and involves less calculation.