Trade Mathematics for Plumbers
(2026 Edition)|| questions and
answers with rationales/graded
A+/2026 update/100% correct
/instant download
Total Questions: 85
Time Allowed: 120 minutes
Passing Score: 70%
Instructions: Select the best answer for each question. Correct answers
are highlighted in bold. A rationale follows each answer.
Section A: Basic Arithmetic & Units of Measurement (Questions 1–15)
1. A plumber measures a pipe length as 3.65 meters. Convert this to millimeters.
A) 36.5 mm
B) 365 mm
C) 3,650 mm
D) 36,500 mm
Rationale: 1 m = 1,000 mm, so 3.65 × 1000 = 3,650 mm.
2. Add: 12 ft 6 in + 8 ft 9 in.
A) 20 ft 15 in
B) 21 ft 3 in
C) 21 ft 3 in
D) 20 ft 3 in
Rationale: 12+8=20 ft, 6+9=15 in = 1 ft 3 in, total 21 ft 3 in.
3. A 150 cm length of copper pipe is cut into 3 equal pieces. Each piece is ___ cm.
A) 50 cm
B) 50 cm
,C) 45 cm
D) 55 cm
Rationale: 150 ÷ 3 = 50 cm.
4. Convert 3/8 inch to a decimal.
A) 0.375
B) 0.375
C) 0.325
D) 0.425
Rationale: 3 ÷ 8 = 0.375.
5. A water tank holds 250 gallons. If 45% is used, how many gallons remain?
A) 112.5 gal
B) 137.5 gal
C) 137.5 gal
D) 125 gal
Rationale: Used = 0.45×250=112.5; Remaining = 250−112.5=137.5.
6. A pipe has an outer diameter of 2.5 inches and wall thickness 0.25 inches. Inner
diameter =
A) 2.25 in
B) 2.0 in
C) 2.0 in
D) 2.75 in
Rationale: ID = OD − 2×thickness = 2.5 − 0.5 = 2.0 in.
7. 1 cubic foot of water weighs about 62.4 lb. How much does 5.5 cu ft weigh?
A) 312 lb
B) 343.2 lb
C) 343.2 lb
D) 372 lb
Rationale: 5.5 × 62.4 = 343.2.
8. A job requires 3¾ hours. Convert to decimal hours.
A) 3.25 hr
B) 3.5 hr
C) 3.75 hr
D) 4.0 hr
Rationale: ¾ = 0.75, so 3.75.
, 9. A plumber
earns 45.50/hour.Whatisovertimepayat1.5×for4hours?A)45.50/hour.Whatisovertim
epayat1.5×for4hours?A)182
B) 273C)∗∗273C)∗∗273**
D) $300
Rationale: 45.50×1.5=68.25, ×4=273.
10. Pipe A is 6.2 m, Pipe B is 4.85 m. Total length?
A) 10.95 m
B) 11.05 m
C) 11.15 m
D) 10.85 m
Rationale: 6.20 + 4.85 = 11.05 m.
11. Subtract 2¾ inches from 5½ inches.
A) 2¼ in
B) 2½ in
C) 2¾ in
D) 3 in
Rationale: 5.5 − 2.75 = 2.75 = 2¾.
12. Convert 18 psi to inches of water column (1 psi ≈ 27.7 in H₂O).
A) 498.6 in
B) 498.6 in
C) 450 in
D) 500 in
Rationale: 18 × 27.7 = 498.6.
13. A 50-foot pipe is cut into 5 equal sections. Each section = ___ ft.
A) 10 ft
B) 10 ft
C) 8 ft
D) 12 ft
Rationale: 50 ÷ 5 = 10.
14. Convert ¼ inch to millimeters (1 in = 25.4 mm).
A) 6.35 mm
B) 6.35 mm
C) 5.35 mm
(2026 Edition)|| questions and
answers with rationales/graded
A+/2026 update/100% correct
/instant download
Total Questions: 85
Time Allowed: 120 minutes
Passing Score: 70%
Instructions: Select the best answer for each question. Correct answers
are highlighted in bold. A rationale follows each answer.
Section A: Basic Arithmetic & Units of Measurement (Questions 1–15)
1. A plumber measures a pipe length as 3.65 meters. Convert this to millimeters.
A) 36.5 mm
B) 365 mm
C) 3,650 mm
D) 36,500 mm
Rationale: 1 m = 1,000 mm, so 3.65 × 1000 = 3,650 mm.
2. Add: 12 ft 6 in + 8 ft 9 in.
A) 20 ft 15 in
B) 21 ft 3 in
C) 21 ft 3 in
D) 20 ft 3 in
Rationale: 12+8=20 ft, 6+9=15 in = 1 ft 3 in, total 21 ft 3 in.
3. A 150 cm length of copper pipe is cut into 3 equal pieces. Each piece is ___ cm.
A) 50 cm
B) 50 cm
,C) 45 cm
D) 55 cm
Rationale: 150 ÷ 3 = 50 cm.
4. Convert 3/8 inch to a decimal.
A) 0.375
B) 0.375
C) 0.325
D) 0.425
Rationale: 3 ÷ 8 = 0.375.
5. A water tank holds 250 gallons. If 45% is used, how many gallons remain?
A) 112.5 gal
B) 137.5 gal
C) 137.5 gal
D) 125 gal
Rationale: Used = 0.45×250=112.5; Remaining = 250−112.5=137.5.
6. A pipe has an outer diameter of 2.5 inches and wall thickness 0.25 inches. Inner
diameter =
A) 2.25 in
B) 2.0 in
C) 2.0 in
D) 2.75 in
Rationale: ID = OD − 2×thickness = 2.5 − 0.5 = 2.0 in.
7. 1 cubic foot of water weighs about 62.4 lb. How much does 5.5 cu ft weigh?
A) 312 lb
B) 343.2 lb
C) 343.2 lb
D) 372 lb
Rationale: 5.5 × 62.4 = 343.2.
8. A job requires 3¾ hours. Convert to decimal hours.
A) 3.25 hr
B) 3.5 hr
C) 3.75 hr
D) 4.0 hr
Rationale: ¾ = 0.75, so 3.75.
, 9. A plumber
earns 45.50/hour.Whatisovertimepayat1.5×for4hours?A)45.50/hour.Whatisovertim
epayat1.5×for4hours?A)182
B) 273C)∗∗273C)∗∗273**
D) $300
Rationale: 45.50×1.5=68.25, ×4=273.
10. Pipe A is 6.2 m, Pipe B is 4.85 m. Total length?
A) 10.95 m
B) 11.05 m
C) 11.15 m
D) 10.85 m
Rationale: 6.20 + 4.85 = 11.05 m.
11. Subtract 2¾ inches from 5½ inches.
A) 2¼ in
B) 2½ in
C) 2¾ in
D) 3 in
Rationale: 5.5 − 2.75 = 2.75 = 2¾.
12. Convert 18 psi to inches of water column (1 psi ≈ 27.7 in H₂O).
A) 498.6 in
B) 498.6 in
C) 450 in
D) 500 in
Rationale: 18 × 27.7 = 498.6.
13. A 50-foot pipe is cut into 5 equal sections. Each section = ___ ft.
A) 10 ft
B) 10 ft
C) 8 ft
D) 12 ft
Rationale: 50 ÷ 5 = 10.
14. Convert ¼ inch to millimeters (1 in = 25.4 mm).
A) 6.35 mm
B) 6.35 mm
C) 5.35 mm
