IBEW Ratio and Proportion

Question 1

A wire crew installs 240 feet of conduit in 6 hours. At the same rate, how many feet will they install in 9 hours?

Accepted Answer

360 feet

Answer

The rate is 240 ÷ 6 = 40 feet per hour, so in 9 hours they install 40 × 9 = 360 feet.

Question 2

If 4 electricians can wire 3 apartments in 2 days, how many apartments can 8 electricians wire in 2 days?

Accepted Answer

6

Answer

Doubling the number of electricians doubles the output, so 8 electricians wire 3 × 2 = 6 apartments in the same 2 days.

Question 3

The ratio of copper wire to aluminum wire used on a job is 5:3. If 40 pounds of copper wire is used, how many pounds of aluminum wire are needed?

Accepted Answer

24 pounds

Answer

Setting up the proportion 5/3 = 40/x gives x = (40 × 3) / 5 = 24 pounds.

Question 4

A blueprint is drawn at a scale of 1 inch = 8 feet. If a room measures 3.5 inches on the blueprint, what is the actual length of the room?

Accepted Answer

28 feet

Answer

Multiply the blueprint measurement by the scale factor: 3.5 × 8 = 28 feet.

Question 5

On a job site, the ratio of journeymen to apprentices is 2:5. If there are 14 journeymen, how many apprentices are on the site?

Accepted Answer

35

Answer

Setting up the proportion 2/5 = 14/x gives x = (14 × 5) / 2 = 35 apprentices.

IBEW - Aptitude Test Practice Test