OAR OAR Math Skills: Word Problems 3 — Questions and Answers
Question 1: An aircraft carrier travels at 28 knots for 4 hours, then at 18 knots for 3 hours. What is the total distance covered in nautical miles?
- 148 nm
- 158 nm
- 166 nm (Correct answer)
- 178 nm
Correct answer: 166 nm
Distance = (28 x 4) + (18 x 3) = 112 + 54 = 166 nautical miles.
Question 2: A training course costs $4,500. The Navy covers 80% and the officer pays the rest in 6 equal monthly installments. How much is each installment?
- $100
- $120
- $150 (Correct answer)
- $180
Correct answer: $150
Officer's share = 20% of $4,500 = $900; monthly installment = $900 / 6 = $150.
Question 3: A pump drains a 12,000-gallon tank at 250 gallons per minute. A second pump draining 150 gallons per minute starts 10 minutes after the first. How many total minutes from start until the tank is empty?
- 30 minutes
- 32 minutes
- 34 minutes (Correct answer)
- 36 minutes
Correct answer: 34 minutes
After 10 min, pump 1 removes 2,500 gal (9,500 remain); combined rate = 400 gpm; 9,500 / 400 = 23.75 min; total = 33.75 min, rounded up to 34 minutes.
Question 4: A jet uses 1,800 lb of fuel per hour cruising and 2,400 lb per hour climbing. A mission has 20 minutes of climb and 2 hours of cruise. How many pounds of fuel are used?
- 3,800 lb
- 4,000 lb
- 4,400 lb (Correct answer)
- 4,800 lb
Correct answer: 4,400 lb
Climb fuel = 2,400 x (20/60) = 800 lb; cruise fuel = 1,800 x 2 = 3,600 lb; total = 4,400 lb.
Question 5: If 5 technicians can service 15 aircraft in 3 days, how many technicians are needed to service 36 aircraft in 4 days?
- 6
- 8
- 9 (Correct answer)
- 10
Correct answer: 9
Rate = 15 / (5 x 3) = 1 aircraft per technician-day; tech-days needed = 36; technicians = 36 / 4 = 9.
Question 6: A navigational chart uses a scale of 1 inch = 15 nautical miles. Two ports measure 6.4 inches apart. If a ship travels between them at 24 knots, how long does the trip take?
- 3 hours
- 3 hours 30 minutes
- 4 hours (Correct answer)
- 4 hours 30 minutes
Correct answer: 4 hours
Actual distance = 6.4 x 15 = 96 nautical miles; time = 96 / 24 = 4 hours.
Question 7: Two communications specialists can encode 45 and 30 messages per hour respectively. Working together, how long will it take them to encode 225 messages?
- 2 hours
- 2 hours 30 minutes
- 3 hours (Correct answer)
- 3 hours 30 minutes
Correct answer: 3 hours
Combined rate = 45 + 30 = 75 messages per hour; time = 225 / 75 = 3 hours.
OAR OAR Math Skills: Word Problems 3
An aircraft carrier travels at 28 knots for 4 hours, then at 18 knots for 3 hours.
What is the total distance covered in nautical miles?