## Now let’s solve questions with this trick

**Question –**A take 5 days to complete a job and B takes 10 days to complete the same job. In how much time they will complete the job together ?

**Solution –**

**Question –**A is twice as efficient as B and can complete a job 30 days before B. In how much they can complete the job together ?

**Solution** –

**Question**– A tank can be filled in 20 minutes. There is a leakage which can empty it in 60 minutes. In how many minutes tank can be filled?

**Solution** –

**Method 1**

⇒ Efficiency of filling pipe = 20 minutes = 1/3 hour = 300%

( As Shobhna and Aswin are facing problem in solving this question, I am solving this question with second method which is also very easy, hope this will make the solution lot easier.)

**Method 2**

⇒ Efficiency of filling pipe = 100/20 = 5%

⇒ Efficiency of leakage pipe = 100/60 = 1.66%

⇒ Net filling efficiency = 3.33%

So tank can be filled in = 100/3.33% = 30 minutes

**Question** – 4 men and 6 women working together can complete the work within 10 days. 3 men and 7 women working together will complete the same work within 8 days. In how many days 10 women will complete this work ?

**Solution –**

**Question** – A and B together can complete a task in 20 days. B and C together can complete the same task in 30 days. A and C together can complete the same task in 30 days. What is the respective ratio of the number of days taken by A when completing the same task alone to the number of days taken by C when completing the same task alone?

**Solution –**

⇒ Efficiency of A and B = 1/20 per day = 5% per day ________________1

⇒ Efficiency of B and C = 1/30 per day = 3.33% per day______________2

⇒ Efficiency of C and A = 1/30 per day = 3.33% per day______________3

Taking equation 2 and 3 together

⇒ B + C = 3.33% and C + A = 3.33%

⇒ C and 3.33% will be removed. Hence A = B

⇒ Efficiency of A = B = 5%/2 = 2.5% = 1/40

⇒ Efficiency of C = 3.33% – 2.5% = 0.833% = 1/120

⇒ A can do the job in 40 days and C can do the job in 120 days he they work alone.

⇒ Ratio of number of days in which A and C can complete the job 1:3.