AIT Mathematics for Trades 5

Question 1

A tradesperson uses 1/3 of a 5-gallon bucket of adhesive on Monday and 2/5 on Tuesday. How many gallons remain?

Accepted Answer

11/15 gal

Answer

Used: 1/3 + 2/5 = 5/15 + 6/15 = 11/15 of 5 gal; remaining = (1 − 11/15) × 5 = 4/15 × 5 = 4/3 gal ≈ 1.33 gal — actually remaining fraction = 4/15, remaining gallons = 4/15 × 5 = 20/15 = 4/3 gal. The answer in gallons = 4/3; the question asks gallons remaining = 4/3 ≈ 1.33. Closest listed = 11/15 gal is what was used, not remaining.

Question 2

A gear with 48 teeth drives a gear with 16 teeth. If the drive gear spins at 300 RPM, how fast does the driven gear spin?

Accepted Answer

900 RPM

Answer

Driven RPM = (48/16) × 300 = 3 × 300 = 900 RPM.

Question 3

A right triangle has legs of 9 ft and 12 ft. What is the length of the hypotenuse?

Accepted Answer

15 ft

Answer

c = √(9² + 12²) = √(81 + 144) = √225 = 15 ft.

Question 4

A job pays a base rate of $22/hr for 40 hours and 1.5× overtime for any hours over 40. If an apprentice works 46 hours, what is the gross pay?

Accepted Answer

$1,078.00

Answer

Regular: 40 × $22 = $880; Overtime: 6 × $33 = $198; Total = $1,078.

Question 5

A 3-phase electrical load draws 15 amps per phase at 480 volts. What is the approximate power in kilowatts? (Power factor = 1, √3 ≈ 1.732)

Accepted Answer

12.47 kW

Answer

P = √3 × V × I = 1.732 × 480 × 15 = 12,470 W ≈ 12.47 kW.

(AIT) Apprenticeship and Industry Training Practice Test

(AIT) Apprenticeship and Industry Training Practice Test

AIT Mathematics for Trades 5