AIT Mathematics for Trades 4

Question 1

A tank is 60% full and contains 240 gallons. What is the full capacity of the tank?

Accepted Answer

400 gal

Answer

Full capacity = 240 / 0.60 = 400 gallons.

Question 2

A wire has a resistance of 0.05 ohms per foot. What is the total resistance of 250 feet of wire?

Accepted Answer

12.5 ohms

Answer

Total resistance = 0.05 × 250 = 12.5 ohms.

Question 3

A rectangular box is 24 inches long, 18 inches wide, and 12 inches tall. What is the surface area in square inches?

Accepted Answer

2,016 sq in

Answer

SA = 2(lw + lh + wh) = 2(432 + 288 + 216) = 2(936) = 1,872 — recalculating: 2(24×18 + 24×12 + 18×12) = 2(432+288+216) = 2×936 = 1,872 sq in.

Question 4

An HVAC technician needs to convert 72°F to Celsius. Which formula applies, and what is the result?

Accepted Answer

C = (F-32) × 5/9 = 22.2°C

Answer

C = (72 − 32) × 5/9 = 40 × 5/9 ≈ 22.2°C.

Question 5

An apprentice must divide a 10-foot board into 6 equal pieces. What is the length of each piece in inches?

Accepted Answer

20 in

Answer

10 ft = 120 in; 120 / 6 = 20 inches per piece.

(AIT) Apprenticeship and Industry Training Practice Test