Dear Naira users!

Please help me find a way out to solve problems related to time and work related problems in which two persons working alternate days. Kindly help me with this.

Dear Aakash!

To solve a time and work question in which efficiency of two or more persons is given and we are asked how many days will they take to complete the given work working alternately.

Let's take an example here.
Ex. A and B take 6 days and 4 days alone to do a piece of work. How many days will they take if working alternately?

Explanation:

Step 1. Calculate the combined efficiency of A and B of 2 days = 1/4 + 1/6 = 5/12
Step 2. Think of a multiple of the numerator part of the above fractional value that should be close to the denominator but it shouldn't exceed the denominator. In the given case, it would be 5 x 2 = 10.

Step 3. Multiply this multiple into both the sides LHS and RHS. We thus get,
Combined efficiency of A and B of 4 days = 10/12 or 5/6

Step 4. Calculate the rest of the work by subtracting the combined efficiency from 1. We get, 1 - 5/6 = 1/6

Step 5. Now, as it's A who starts the work, therefore, after working for 4 days it's once again A's turn whose 1 day's efficiency is given as 1/6.
Which means he will take one day to complete the remaining work.

Step 6. Total number of days required = 4 + 1 = 5 days.

We hope it helps. You can drop a query here if anything you want to discuss. You can also go to the link to get more such explanations on the page.

http://smartkeeda.com/Quantitative_Aptitude/Arithmetic/Time_and_Work/newest/all/

Regards,
Smartkeeda

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