AIT Mathematics for Trades 3

Question 1

An electrician needs to run conduit at a 30° angle. If the horizontal run is 10 feet, what is the approximate length of conduit needed? (sin 30° = 0.5, cos 30° ≈ 0.866)

Accepted Answer

11.55 ft

Answer

Conduit length = horizontal run / cos 30° = 10 / 0.866 ≈ 11.55 ft.

Question 2

A welder needs to fill a cylindrical tank with a radius of 3 ft and a height of 5 ft. What is the volume? (π ≈ 3.14)

Accepted Answer

141.3 cu ft

Answer

V = π × r² × h = 3.14 × 9 × 5 = 141.3 cu ft.

Question 3

Bolt holes on a flange are spaced equally. If 8 holes are placed on a 12-inch diameter bolt circle, what is the center-to-center arc spacing in inches? (π ≈ 3.14)

Accepted Answer

4.71 in

Answer

Circumference = π × 12 = 37.68 in; spacing = 37.68 / 8 = 4.71 in.

Question 4

A piece of steel bar stock weighs 3.5 lbs per foot. An apprentice needs 7 pieces each 2.5 feet long. What is the total weight?

Accepted Answer

61.25 lbs

Answer

Total length = 7 × 2.5 = 17.5 ft; weight = 17.5 × 3.5 = 61.25 lbs.

Question 5

A roof has a 6:12 pitch (rise:run). If the horizontal run is 18 feet, what is the total rise?

Accepted Answer

9 ft

Answer

Pitch 6:12 means 6 inches rise per 12 inches run; 6/12 × 18 ft = 9 ft rise.

(AIT) Apprenticeship and Industry Training Practice Test

(AIT) Apprenticeship and Industry Training Practice Test

AIT Mathematics for Trades 3