Question

C takes twice the number of days to do a piece of work than a takes. A and b together can do it in 6 days while b and c can do it in 10 days. In how many days a alone can do the work

Answer 1

Answer:

15 days

Step-by-step explanation:

A+B in 6 days

B+C in 10 days

in sense of work

suppose each work in a day

A works A, B works B, C works C

A+B = 1/6

B+C =1/10

then

A+B+C = 1/6+1/10

A+B+A/2 = 7/60

( Work of A twice than C because C takes twice days than A )

2A+B+A = (7/60 )×2=7/30

3A+B = 7/30

now

equation 1 -------

A+B= 1/6

equation 2-------

3A+B = 7/30

if

equation 2 - equation 1

then,

2A = 7/30-1/6 = 7-5/30 = 2/30 =1/15

then A work in 15 days