Question

The time required to do a job varies inversely as the number of people working. It takes 5hr for 7 bricklayers to build a park well. How long will it take 10 bricklayers to complete the job? (round answer to 1 decimal place)

Answer 1

Answer

3.5 hours.

Explanation

The first step is to calculate the constant of proportionality.

t ∝ 1/n

t = k/n   Where t = time, K= constant and n = number of people

t = k/n

k =tn

   = 5×7 = 35

The equation becomes;

t = 35/n

for n = 10,

t = 35/10

  t = 3.5 hours.