It takes 15 men working steadily 4 days to dig the foundation for a new apartment. How many days would it have taken 25 men working at the same rate to dig the foundation? Express your answer as a decimal to the nearest tenth.

2 answers

15 / 4 = 25 / x

15x = 100

x = 6.7 days
15 men -> 1 apartment/4 days

=> 5 men -> 1 apartment/12 days

=> 25 men -> 5 apartments/12 days

So, if 25 men produce the foundations for 5 apartments in 12 days, then they will produce a foundation for ONE apartment in 12 days/5 = 2.4 days