Question

1). Sunil and Santosh together can finish a work in 30 days. They worked for it for 20 days and then Santosh left. The remaining work was done by Sunil alone in 20 more days, Santosh alone can finish the work in
A). 52 days
B). 30 days
C). 48 days
D). 60 days​

Answer 1

         Santosh can finish the work alone in 60 days.

• Let’s assume total work is 30 units.
• Work done per day by Santosh and Sunil is 1 unit.
• Let’s assume X is per day work done by Santosh and Y is the per day work done by Sunil.
• So, 20(X+Y)+20X=30
• We can also interpret the above equation as Santosh and Sunil together work for 20 days, so, they finish 20 units of work.
• The remaining 10 units of work are completed by Santosh in 20 days.
• So now Santosh’s per day work is 1/2 unit.
• So X=1/2
• So Santosh does ½ unit work in one day.
• So if Santosh does 30 units of work alone, it will take him 60 days.