Aptitude - Time and Work - Discussion
Discussion Forum : Time and Work - General Questions (Q.No. 22)
22.
A and B can complete a work in 15 days and 10 days respectively. They started doing the work together but after 2 days B had to leave and A alone completed the remaining work. The whole work was completed in :
Answer: Option
Explanation:
| (A + B)'s 1 day's work = |  |
1 | + | 1 |  |
= | 1 | . |
| 15 | 10 | 6 |
| Work done by A and B in 2 days = | |
1 | x 2 | |
= | 1 | . |
| 6 | 3 |
| Remaining work = | |
1 - | 1 | |
= | 2 | . |
| 3 | 3 |
| Now, | 1 | work is done by A in 1 day. |
| 15 |
 |
2 | work will be done by a in | |
15 x | 2 | |
= 10 days. |
| 3 | 3 |
Hence, the total time taken = (10 + 2) = 12 days.
Discussion:
40 comments Page 3 of 4.
Chuchu said:
9 years ago
A = 15.
B = 10.
Work per day = 1.
We can get 1/15 and 1/10.
We can solve it like this:.
= ( (1 * 10) + (15 * 10) ) + ((1 * 15) + (15 * 10) ) ----> Cross Multiply.
We will get: then add.
= 10/150 + 15/150.
Then simplify:
= 25/150.
= 1/6.
Then minus the number of work per day.
= 1/6 - 1.
You will get the following answer then multiply to the number of work of the person had left.
= 5/6 * 1/10 ---> Cross Multiply.
= 50/6 ---> Get the whole number.
= 12.
B = 10.
Work per day = 1.
We can get 1/15 and 1/10.
We can solve it like this:.
= ( (1 * 10) + (15 * 10) ) + ((1 * 15) + (15 * 10) ) ----> Cross Multiply.
We will get: then add.
= 10/150 + 15/150.
Then simplify:
= 25/150.
= 1/6.
Then minus the number of work per day.
= 1/6 - 1.
You will get the following answer then multiply to the number of work of the person had left.
= 5/6 * 1/10 ---> Cross Multiply.
= 50/6 ---> Get the whole number.
= 12.
Deepak kumar dalabehera said:
9 years ago
B works for 2 days = 1/10 * 2 = 1/5.
Remaining work was done by A = 1 - 1/5 = 4/5.
Total time has taken 4/5 * 15 = 12 days.
Remaining work was done by A = 1 - 1/5 = 4/5.
Total time has taken 4/5 * 15 = 12 days.
Sunny said:
9 years ago
@Chinna.
How 1/6 comes?
How 1/6 comes?
Shyambhai said:
9 years ago
This can be solved by the following method:
(1 - 2/10) * 15 - 2) + 2.
((10 - 2/10) * 15 - 2) + 2.
((8/10) * 15 - 2) + 2.
((4/5 * 15 - 2) + 2.
(12 - 2) + 2.
= 10 + 2 = 12 days --> Answer.
(1 - 2/10) * 15 - 2) + 2.
((10 - 2/10) * 15 - 2) + 2.
((8/10) * 15 - 2) + 2.
((4/5 * 15 - 2) + 2.
(12 - 2) + 2.
= 10 + 2 = 12 days --> Answer.
Abdu Razak said:
10 years ago
Here B done 20%.
So A have to do 80 %.
80 % of 15 = 13.
So A have to do 80 %.
80 % of 15 = 13.
Inna Reddy Chilakala said:
10 years ago
A = 15.
B = 10.
After 2 days B had to leave.
X/15+2/10 = 1.
2X+6 = 30.
2X = 24.
X = 12.
B = 10.
After 2 days B had to leave.
X/15+2/10 = 1.
2X+6 = 30.
2X = 24.
X = 12.
Swathi said:
10 years ago
29x/25-x = 40 find out x value.
Vivek said:
1 decade ago
2 days already completed so.
Rahul jha said:
1 decade ago
Why we add 10+2 days?
Sona said:
1 decade ago
Why 2 is to be added at the end?
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