Simple Rule for work and time questions:

• If “A” finishes a work in 10 days, it means the work of “A” in 1 day is 1/10.
• If 1-day work of “A” is 1/8, then “A” will finish full work in 8 Days.

Example 1. Ravi completes a work in 12 days. How much works he does in 1 day?

Answer: 1-day work = 1/12

Example 2.Shaym can complete a work in 4 days. How much work he will do in 2 days?

Answer: 1-day work of shyam = 1/4

2 day work = 2 X (1-day work) = 2 X(1/4) = 1/2

Example 3.Ranjan completes 1/5 work in 1 day. How many days he will take to complete the full work?

Answer: 1-day work = 1/5

Total time to finish the work = 5 days

Example 4. Suresh completes 1/2 work in 4 days. How many days will he take to complete the full work?

Answer: 1/2 work in 4 days, it means full work in 2X4 = 8 days.

Example 5. Raju completes a work in 6 days and Rohit completes that work in 12 days. If they both work together then how many days, they will take to complete the full work?

Answer: 1-day work of Raju = 1/6

1-day work of Rohit = 1/12

1-day work of Raju &Rohit together = 1/6 + 1/12 = 3/12 = 1/4 

Total days taken by Raju &Rohit together = 4 Days