Question

A can complete a piece of work in 8 hours, b can complete in 10 hours and c in 12 hours. if a,b, c start the work together but a laves after 2 hours. find the time taken by b and c to complete the remaining work.

Answer 1

A can do the work in 8 hrs
B can do the work in 10 hrs
c can do the work in 12 hrs

in 1 hr A does =1/8 part
in 1 hr B does =1/10 part
in 1 hr C does =1/12 part

together in 1 hr they does =(1/8+1/10+1/12)
= (15+12+10/120)
= 37/120
after working for 2 hrs A left
work done = (37/120×2)=37/60 part
B and C can do =(37/120-1/8) part
=(37-15/120) part
=22/120=11/60
work remaining = (1- 37/120)=113/120

work. time
37/120. 1
113/120. x
x=1/37/120×113/120
= 1/37×120/37×113/120
=113/1369
= 12whole 43/113 hrs

Answer 2

Answer:

Step-by-step explanation:

A can do a work in 8 days

B in 10 days

C in 12 days

LCM for 8,10,12 is 120=total work

A's 1 day work will be 120/8=15

similarly B's 1 day work=12 and C's 1 day work =10

total work =A+B+C=15+10+12=37/hr

for 2hrs=37*2=74(completed)

120-74=46(incomplete)

it is to be completed by B+C

B+C's 1 day work=12+10=22

therefore 46/22=2 1/11