Question

The time is takes to build a skyscraper is proportional to its height and inversely proportional to the number of construction workers. If it takes 10 workers 2.5 years to build a 20 story building, how long will it take 70 workers to build a 60 story building?

Answer 1

`t = 1.07 years`

Step-by-step explanation:

As we know that time to build is proportional to height and inversely proportional to the number of workers

so we can say that

`t = c(H)/(N)`

here we know that 10 workers took 2.5 years to build 20 story building

so we will have

`2.5 years = c(20)/(10)`

`c = (2.5)/(2)`

now we will have 70 workers to build 60 story building

so we have

`t = (2.5)/(2) * (60)/(70)`

`t = 1.07 years`