Q13----------------Raju can do a piece of work in 10 days,Vicky in 12 days .................?

Question

Q13----------------Raju can do a piece of work in 10 days,Vicky in 12 days and Tinku in 15 days.They all start the work together,but Raju leaves after 2 days and Vicky leaves 3 days before the work is completed.In how many days the work is completed.
a. 5 days
b. 6 days
c. 7 days
d. 8 days

Answer 1

Raju does 1/10 per day.
Vicky does 1/12 per day.
Tinku does 1/15 per day.

After 2 days Raju has done 2/10, and that is his sole contribution.

Vicky leaves 3 days before the work is completed. Tinku is working by himself once Vicky leaves, and he does 1/15 per day, so she leaves when Tinku has 3*(1/15) = 3/15 = 1/5 to do by himself.

Subtracting what Raju does (1/5) and what Tinku must do by himself (1/5), that leaves 3/5 to be completed by Vicky and Tinku.

x * (1/12 + 1/15) = 3/5
x * (5/60 + 4/60) = 3/5
x * (9/60) = 3/5
x * (3/20) = 3/5
x = 4

This means that Vicky and Tinku must work 4 days together, from the start of the project. Adding the 3 days that Tinku must work by himself, it takes 7 days to complete. That's you answer (c).

Answer 2

C. 7 Days

Answer 3

c. 7days

Answer 4

b.6days