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2 men and 3 boys can do a piece of work in 10 days while 3 men and 2 boys can do the same work in 8 days. In how many days can 2 men and 1 boy do the work ?
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- 8 days
- 7 days
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12 1 days 2 - 2 days
Correct Option: C
According to the question, 20 men + 30 boys = 24 men + 16 boys
∴ 4 men = 14 boys
⇒ 2 men = 7 boys
⇒ 2 men + 1 boy = 8 boys
⇒ 2 men + 3 boys = 10 boys
By M1 D1 = M2 D2
⇒ 10 × 10 = 8 × D2
| ⇒ D2 = | = | = 12 | days | |||
| 8 | 2 | 2 |
Aliter :
Using Rule 11,
Here, A1 = 2, B1 = 3, D1 = 10
A2 = 3, B2 = 2, D2 = 8
A3 = 2, B3 = 1
| Required time = | days | |
| D1(A1B3 - A3B1) - D2(A2B3 - A3B2) |
| = | days | |
| 10(2 × 1 - 2 × 3) - 8(3 × 1 - 2 × 2) |
| = | = 12 | days | ||
| -40 + 8 | 2 |
