Problema Solution
there are three pipes. the first and second pipe can do the job for 20 hours.the first and the third pipe can finish the job for 30 hours while the second and the third pipe can do the job for 25 hours. how long would they finish the job altogether?
Answer provided by our tutors
a+b, 1hr completes 1/20 of the work
b+c , 1hr completes1/30 of the work
a+c, 1hr completes 1/25 of the work
combine all the equation,
2(a+b+c)=1/20 + 1/30 + 1/25
2(a+b+c)=7/25
(a+b+c)=7/50
all three complete the work in 50/7 hr