Question

a and b can do a piece of work in 72 days .b and c can do it in 120 days . a and c can do it in 90 days. i what time can a alon do it​

Answer 1

Answer:

according to question

a+b=72

b=72-a ------------eq1

now

b+c=120

c=120-b ------------eq2

now

a+c=90

a+120-72+a=90               [using equation 1 and 2]

2a=42

a=21 days me kaam karega

Step-by-step explanation: