A and B can do a piece of work in 30 days and 18 days respectively. A started the work alone and then after 6 days, B joined him till the completion of the work. In how many days has the whole work completed?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e 15.
| Understanding |
|
No of days taken by A = 30 No of days taken by B = 18 Find the LCM of (30,18) = 90 Total work that is done by A per day= 3 Total work that is done by B per day= 5 Let x is the number of days A and B work together. No of days taken by A alone = 6. According to the question; 3 × 6 + (5 + 3) x = 90 x = 9 Total number of days for the whole work= 9 + 6 = 15days |