Question

A and B can do a piece of work in 40 days, B and C can do it in 120 days. If B alone can do it in 180 days, in how many days will A and C do it together?​

Answer 1

Answer:

hii

your answer is here !

Step-by-step explanation:

A + B take 40 days. B alone takes 180 days.

∴ A will take 1/40 – 1/180 = 7/360 ⇒ 360/7 days.

B + C take 120 days.

∴ C alone will take 1/120 – 1/180 = 1/360

i.e. 360 days.

∴ A & C together will take 7/360 + 1/360

= 8/360 ⇒ 360/8 = 45 days to complete the work.

follow me !

Answer 2

heyya

a+b can do it in 40 days..

task completed in 10 day = 1/4th of the whole

3/4th part of the work done by a+b+c in 20 daysthen these three can complete a whole amount of work in 20 x4/3=80/3 days

now talking of the efficiency of all three

a+b    &      a+b+c

40                80/3

120              80      lcm 240

2-effe           3-effe

effe of c=1

then b-effe=1/3

1+1/3+a's effe=3

a effe= 5/9

time taken by a=240/5 x 9=48x9=432days