Question

Ajay and vijay can do a piece of work in 28 days. With the help of manoj, they can finish it in 21 days. How long will manoj take to finish the work all alone? *

Answer 1

Time taken by Ajay and Vijay to do a piece of work = 28 days

→ Ajay and Vijay one day's work = 1/28

→ Time taken by Ajay , Vijay and Manoj to do a piece of work = 21 days

→ Ajay and Vijay one day's work + Manoj one day's work  = 1/21

→  1/28 +  Manoj one day's work = 1/21

→  Manoj one day's work = 1/21 - 1/28

                                         = 1/84

So, Manoj can Accomplish this work while working alone in 84 days.