Question

Sita can finish typing a 100 page document in 9 hours, Mita in 6 hours and Rita in 12 hours. How long will they take to type a 100 page document if they work together?

Answer 1

The given details are,

Work done by Sita in 1 hour = 1/9

Work done by Mita in 1 hour = 1/6

Work done by Rita in 1 hour = 1/12

Work done by Sita, Mita and Rita together in 1 hour = 1/9 + 1/6 + 1/12

= (4+6+3)/36 (by taking LCM for 9, 6 and 12 which is 36)

= 13/36

∴ Time taken by all three together to complete the work = 1/(13/36) = 36/13 hours.