Question

A, b and c can together do some work in 72 days. A and b together do two times as much work as c alone. A and c together can do four times as much work as b alone. Find the time taken by c alone to do the whole work?

Answer 1

Answer:

216 Days

Step-by-step explanation:

Let say a's 1 day work = a

Let say b's 1 day work = b

Let say c's  1 day work = c

a & b together 1 day work = a + b  = 2c     eq 1

Similarly a & c together 1 day work a + c = 4b    eq 2

eq 2 - eq 1

=> c - b = 4b - 2c

=> 3c = 5b

=> b = 0.6c

putting in eq 1

=> a + 0.6c = 2c

=> a = 1.4c

a , b & c together 1 day work = a + b + c  =  1.4c + 0.6c + c

= 3c

72 Days work = 72*3c = 216c

c alone will take 216c/c = 216 Days