Question

If 12 workers can dig a tunnel in 100 days, how long will it take 20 workers to dig the tunnel

Answer 1

Answer:

60 days.

Step-by-step explanation:

This is  a proportion question. You compare two ratios. Unfortunately it is an inverse ratio.

12 = k/100                   Multiply both sides by 100

1200 = k

20 = k/x                       Multiply both sides by x

20x = k

20x = 1200                 Divide by 20

20x/20 = 1200/20

x = 60 days.  

An inverse proportion works by making a constant k. The  constant k makes the days shorter when the number of people increases. You should expect that. More people , less time.