SOLUTION: Inverse variation, Solve following problem 1. The time t required to do a job varies inversely as the number of people p working. It takes 5 hours for 7 bricklayers to complete

Question 1175777: Inverse variation, Solve following problem
1. The time t required to do a job varies inversely as the number of people p working. It takes 5 hours for 7 bricklayers to complete a certain job. How long will it take for 10 bricklayers to complete the job?
Found 2 solutions by math_helper, Theo:
Answer by math_helper(2461) (Show Source): You can put this solution on YOUR website!
Each bricklayer does 1/(5*7) = 1/35 job per hour (so one bricklayer would take 35hrs to do the job on their own)

Knowing this, 10 bricklayers can do 10/35 job per hour

Thus, the total time for 10 bricklayers to do 1 job is:
1/(10/35) = 35/10 = 3.5hrs
Answer by Theo(13342) (Show Source): You can put this solution on YOUR website!
inverse variation formula is t = k / p
when t = 5 and p = 7, formula becomes 5 = k / 7
solve for k to find k = 35.
that's your constant of variation.
it is solved for from the given values of t and p.
if you are given a new value to t, it is used to solve for p.
if you are given a new value to p, it is used to solve for t.
if you are given two new values for both t and p, then a new value of k is solved for.
in this problem you are given a new value for p and asked to solve for t.
when p = 10, formula becomes t = 35 / 10
solve for t to get t = 3.5
that's your answer.

RELATED QUESTIONS
The time T to do a job varies inversely as the number of people P working. It takes... (answered by richwmiller)
The time T required to do a job varies inversely as the number of people P working. It... (answered by mananth)
The times t required to do a job varies inversely as the number of people P working. It... (answered by stanbon)
the time t required to do a certain job varies inversely as the number of people in... (answered by ankor@dixie-net.com)
Using k as the constant of variation, write the equation of variation for each following. (answered by mananth)
the time t required to empty a water tank varies inversely as the rate of pumping p. a... (answered by josmiceli)
The time required to complete a job varies inversely as the number of people working. It... (answered by fractalier)
Write an equation expressing the variation described; then use it to solve the problem (answered by josgarithmetic)
The times t required to do a job inversely as the number of people P working. It takes 6... (answered by josgarithmetic)