It takes 10 people 5 days to complete a piece of work at a factory when working 2 hours a day. Working at the same pace, how many days will it take 2 people to do the same work, if they are working 5 hours a day?
Answers
10 people : 5 days : 2 hours a day
The number of people working is inversely proportional to the number of days needed.
⇒ The more people working, the fewer days they need
Find the number of days needed for 1 person to complete the work:
10 ÷ 10 people : 5 x 10 days : 2 hours a day
1 person : 50 days : 2 hours a day
Find the number of days needed for 2 person to complete the work:
1 x 2 person : 50 ÷ 2 days : 2 hours a day
2 people : 25 days : 2 hours a day
The number of hours worked is inversely proportional to the number of days needed.
⇒ The more hours worked in a day, the fewer days they need
Find the number of days needed if they worked 1 hour a day :
2 people : 25 x 2 days : 2 ÷ 2 hours a day
2 people : 50 days : 1 hours a day
Find the number of days needed if they worked 5 hour a day :
2 people : 50 ÷ 5 days : 1 x 5 hours a day
2 people : 10 days : 5 hours a day
Answer: It will take 10 days