Question

if 3 men or 9 boys can finish a work in 21 days. in how many days can 5 men and 6 boys together do the same peice of work ​

Answer 1

Step-by-step explanation:

3 men or 9 boys finish a work in 21 days

3men=21days

1 man= 21×7

1 man=147 days

9 boys=21 days

1 boy=21×9

1 boy=189days

According to question

To finish the same piece of work by 5 men and 6 boys

5 men + 6 boys

147/5(1 man= 147 days) + 189/6(1 boy=189 days)

147/5 + 189/6

1527/30

509/10

50.9 days

Answer 2

Answer:

3 men = 9 boys

1 men = 9/3 = 3 boys

3 men can complete in 21 days

9 boys in 21 days

1 men can complete in 63 days

1 boy can complete in 189 days

5 men = 15 boys

15 + 6 = 21

5 men and 6 boys together = 189/21 = 9 days