NCDAP Mathematical Operations & Problem Solving 4 — Questions and Answers
Question 1: A bag contains 4 red, 6 blue, and 2 green marbles. What is the probability of randomly picking a blue marble?
- 1/2 (Correct answer)
- 1/3
- 2/3
- 1/4
Correct answer: 1/2
There are 6 blue out of 12 total marbles, so probability = 6/12 = 1/2.
Question 2: Evaluate: |−15| + |−8|
- 23 (Correct answer)
- 7
- −7
- −23
Correct answer: 23
Absolute values are always positive: 15 + 8 = 23.
Question 3: A tank holds 120 gallons and is 3/4 full. How many gallons are currently in the tank?
- 90 (Correct answer)
- 80
- 95
- 85
Correct answer: 90
3/4 × 120 = 90 gallons are in the tank.
Question 4: If the average of 5 test scores is 82, what is the total sum of all 5 scores?
- 410 (Correct answer)
- 400
- 415
- 420
Correct answer: 410
Average = sum ÷ count, so sum = 82 × 5 = 410.
Question 5: What is 2,400 ÷ 0.06?
- 40,000 (Correct answer)
- 400
- 4,000
- 400,000
Correct answer: 40,000
2,400 ÷ 0.06 = 2,400 × (100/6) = 40,000.
Question 6: A ladder leans against a wall. The base is 6 feet from the wall and the ladder is 10 feet long. How high up the wall does the ladder reach?
- 8 feet (Correct answer)
- 7 feet
- 9 feet
- 6 feet
Correct answer: 8 feet
Using the Pythagorean theorem: h² + 6² = 10², so h² = 64, h = 8 feet.
Question 7: Simplify: (3x²)(4x³)
- 12x⁵ (Correct answer)
- 7x⁵
- 12x⁶
- 7x⁶
Correct answer: 12x⁵
Multiply coefficients (3 × 4 = 12) and add exponents (2 + 3 = 5) to get 12x⁵.
NCDAP Mathematical Operations & Problem Solving 4
A bag contains 4 red, 6 blue, and 2 green marbles.
What is the probability of randomly picking a blue marble?