Five men can do a piece of work in 2 hours, which 7 women could do in 3 hours, or 9 children in 4 hours. How long would 1 man, 1 woman and 1 child together take to do the work?
Answers
Answer:
401/315
Step-by-step explanation:
5 men = 2 hrs
one men = 2/5 hrs
seven women = 3 hrs
one women = 3/7 hrs
9 children. = 4 hrs
1 child = 4/9 hrs
total time = 2/5 + 3/7 + 4/9
= 126/315 +135/315 + 140/315
= 401/315 hrs will be taken by one women one men and one child
1 man, 1 woman and 1 child together take about 5.7 hrs
Given:
Five men can do a piece of work in 2 hours
7 women could do in 3 hours
9 children in 4 hours
To Find:
Time taken by 1 man, 1 woman and 1 child together to do the work
Solution:
Five men can do a piece of work in 2 hours,
Total work = 5 * 2 = 10 Man hours
Hence 1 Man work in 1 hr = 1/10
7 women could do in 3 hours,
Total works = 7 * 3 = 21 Woman hrs
Hence 1 Woman work in 1 hr = 1/21
9 children in 4 hours
Total works =9 * 4 =36Child hrs
Hence 1 Child work in 1 hr = 1/36
Total Work by 1 Man , 1 Woman and 1 child in 1 hr
= 1/10 + 1/21 + 1/36
= (126 + 60 + 35 )/1260
= (221)/1260
Time taken = 1260/221 ≈ 5.7 hrs
1 man, 1 woman and 1 child together take about 5.7 hrs