OAA Mathematics 4 — Questions and Answers
Question 1: What is the least common multiple (LCM) of 6 and 8?
- 12
- 48
- 24 (Correct answer)
- 16
Correct answer: 24
The multiples of 6 are 6, 12, 18, 24 and of 8 are 8, 16, 24; the LCM is 24.
Question 2: A scale drawing uses 1 inch to represent 50 miles. If a road is 3.5 inches long on the drawing, how long is the actual road?
- 150 miles
- 175 miles (Correct answer)
- 200 miles
- 125 miles
Correct answer: 175 miles
3.5 × 50 = 175 miles.
Question 3: Which of the following is NOT a property of a parallelogram?
- Opposite sides are parallel
- All angles are right angles (Correct answer)
- Opposite angles are equal
- Opposite sides are equal in length
Correct answer: All angles are right angles
A parallelogram does not require right angles; that is a property of a rectangle.
Question 4: If y = 3x + 2, what is y when x = –4?
- –10 (Correct answer)
- 14
- –14
- 10
Correct answer: –10
y = 3(–4) + 2 = –12 + 2 = –10.
Question 5: A data set has a mean of 50 and 8 values. One value of 90 is added. What is the new mean?
- 54.4 (Correct answer)
- 55
- 56
- 52
Correct answer: 54.4
Original sum = 50 × 8 = 400; new sum = 400 + 90 = 490; new mean = 490 ÷ 9 ≈ 54.4.
Question 6: Simplify: (3x²)(4x³)
- 7x⁵
- 12x⁶
- 12x⁵ (Correct answer)
- 7x⁶
Correct answer: 12x⁵
Multiply the coefficients (3 × 4 = 12) and add the exponents (2 + 3 = 5) to get 12x⁵.
Question 7: A car travels 270 miles in 4.5 hours. What is its average speed?
- 55 mph
- 65 mph
- 60 mph (Correct answer)
- 70 mph
Correct answer: 60 mph
Speed = distance ÷ time = 270 ÷ 4.5 = 60 mph.
OAA Mathematics 4
What is the least common multiple (LCM) of 6 and 8?