Question

On a new construction site, an electrician can install a new light fixture in 20 minutes. A project calls for 24 new fixtures to be installed on each of 4 floors. If a work day is 8 hours, how many work days will it take two electricians to complete the installations?

Answer 1

1)
We calculate the total number of new light fixtures.

Total number of new light fixtures=(24 new fixtures/1 floor)(4 floors)=
=96 new fixtures.

2)
We calculate the total number of work hours
20 minutes=20 minutes * (1 hour/60 minutes)=1/3 hour.

1 electrician-----------1/3 hour----------1 new  fixture
2 electricians----------      x    ------------96 new fixtures

1 elec.*1/3 hour*96 nex fixtures=2 elect. * x * 1 new fixture.

x=(1 elec. *1/3 hour * 96 nex litght fixtures) / (2 elect.* 1 new fixture)=
=16 hours.

3)
We calculate the total number of days that it take two electricians to complete the installations.

1 day-------------8 work hours
x------------------16 work hours

x=(1 day* 16 work hours) / (8 work hours)=2 days

Answer: 2 days.