Question

A and B together takes 5 days to do a work b and c take 7 days to do the same as and a and c take 4 days to do it who among these will take the least time if put to do it alone

Answer 1

As give b=4
b=7-c
b=7-4
b=3
as b=3
then
A=5-b
a=5-3
A = 2
therefore A took 2 days which is least

Answer 2

■WE FIND THEIR ONE DAY WORK
A AND B 1 DAY WORK = 1/5
B AND C 1 DAY WORK = 1/7
A AND C 1 DAY WORK = 1/4
■ THEY ALL DO WORK IN = 1/5 +1/4 +1/7
= 83/140 = 140/83days
■A alone do in = total - b+c
= 83/140-1/7= 83-20 /140= 63/140= 140/63 days
■B ALONE DO IN = total - a+c
= 83/140-1/4 = 83-35/140 = 48/140 = 140/48 days
■C ALONE DO IN = total- b+A
= 83/140-1/5 = 83-28/140= 55/140=140/55 days
■ so least days is taken by A
■IF IT IS RIGHT
PLEASE MARK IT AS A BRAINLIEST