Aptitude - Time and Work - Discussion
Each of the questions given below consists of a question followed by three statements. You have to study the question and the statements and decide which of the statement(s) is/are necessary to answer the question.
How many workers are required for completing the construction work in 10 days? | |
I. | 20% of the work can be completed by 8 workers in 8 days. |
II. | 20 workers can complete the work in 16 days. |
III. | One-eighth of the work can be completed by 8 workers in 5 days. |
| I. | 20 | work can be completed by (8 x 8) workers in 1 day. |
| 100 |
Whole work can be completed by (8 x 8 x 5) workers in 1 day.
| = | 8 x 8 x 5 | workers in 10 days = 32 workers in 10 days. |
| 10 |
II. (20 x 16) workers can finish it in 1 day.
| |
(20 x 16) | workers can finish it in 10 days. |
| 10 |
32 workers can finish it in 10 days.
| III. | 1 | work can be completed by (8 x 5) workers in 1 day. |
| 8 |
Whole work can be completed by (8 x 5 x 8) workers in 1 day.
| = | 8 x 5 x 8 | workers in 10 days = 32 workers in 10 days. |
| 10 |
Any one of the three gives the answer.
Correct answer is (E).
Work per "x" men per day = 1/10x.
When 5 workers didn't join work per men, per day = 1/(x-5) * 12.
Equating both the above equations we get x = 30.
Can anyone answer this?
1-day work of 1w = 1/8 * 8.
1/5th part is completed by 8w => 1w part =1/8 * 8 * 5.
1 worker's 1day work is 1/(8 * 8 * 5).
For 10 days work ->10/(8 * 8 * 5) = 1/32.
=> 32 workers are needed to complete 10 days work.