**Shortcut 68:**

Three men working together

Question:

A can do a work in 40 days, B in 50 days and C in 60 days. If they work together, how long will they take to complete the work?

Answer:

A = 40

B = 50

C = 60

Substitute the values in the above formula, we get

Time taken together = (40 x 50 x 60)/(40 + 50 + 60)

= 16.21 days

**Shortcut 69:**

Work done

*Work Done=per day work*number of days *

Question:

A can do a piece of work in 40 days. What is the fraction of work done by him in 25 days?

Answer:

Per day work of A = 1/40

Number of days for which A worked = 25

Work done = (1/40) x 25

= 5/8

**Shortcut 70:**

Remaining work

Question:

A can do a work in 30 days, B in 40 days. A works for 9 days and the remaining work is done by B. What is the total number of days to complete the work?

Answer:

Time taken to complete the work

= Remaining work x time to finish full work

Remaining work for B = 1 – Work done by A

Work done by A = (1/30) x 9 = 3/10

Remaining work for B = 1 – 3/10 = 7/10

Time taken by B to complete the remaining work

= 7/10 x 40

= 28 days

Total time taken = 28 + 9 = 37 days

**Shortcut 71:**

Salary ratio of two men working together

Question:

A can do a work in 20 days and B can do the same work in 40 days. They both work together and get a combined salary of Rs. 3000. What is the salary of A?

Answer:

SA = Salary of A

SB = Salary of B

A = 20; B = 40

SA : SB = 40 : 20 = 2 : 1

SA = [2/(2+1)] x 3000

= 2000

Salary of A = Rs. 2000

**Shortcut 72:**

Salary ratio of three men working together

Question:

A can do a work in 30 days B in 40 days and C in 50 days. If they all work together, what will the ratio between their salaries?

Answer:

A = 30

B = 40

C = 50

SA : SB : SC = (1/30) : (1/40) : (1/50)

The ratio between their salary = 20 : 15 : 12