ATAR Calculation Fundamentals 4 — Questions and Answers
Question 1: If 5 workers can complete a job in 8 days, how many days will 10 workers take to complete the same job?
- 2 days
- 4 days (Correct answer)
- 6 days
- 16 days
Correct answer: 4 days
Inverse proportion: 5×8 = 10×d, so d = 40÷10 = 4 days.
Question 2: What is the value of (−3)^4?
- −81
- 81 (Correct answer)
- −12
- 12
Correct answer: 81
(−3)^4 = (−3)×(−3)×(−3)×(−3) = 9×9 = 81 (even exponent gives positive result).
Question 3: A tank holds 500 litres. If 35% is already filled, how many litres are still needed to fill it?
- 175 L
- 325 L (Correct answer)
- 265 L
- 300 L
Correct answer: 325 L
35% filled = 0.35×500 = 175 L; remaining = 500 − 175 = 325 L.
Question 4: Which expression equals 64^(1/3)?
- 8
- 4 (Correct answer)
- 16
- 32
Correct answer: 4
64^(1/3) is the cube root of 64; since 4³ = 64, the answer is 4.
Question 5: Solve: 2(3x + 4) = 5x + 14
- x = 4
- x = 6 (Correct answer)
- x = 2
- x = 3
Correct answer: x = 6
Expand: 6x + 8 = 5x + 14; subtract 5x and 8 from both sides: x = 6.
Question 6: What is the median of the dataset: 4, 9, 2, 7, 5, 11, 3?
- 5 (Correct answer)
- 7
- 4
- 9
Correct answer: 5
Sorted: 2, 3, 4, 5, 7, 9, 11 — the middle (4th) value is 5.
Question 7: A price increased from $80 to $100. What is the percentage increase?
- 20%
- 25% (Correct answer)
- 15%
- 30%
Correct answer: 25%
Percentage increase = (100−80)/80 × 100 = 20/80 × 100 = 25%.
ATAR Calculation Fundamentals 4
If 5 workers can complete a job in 8 days, how many days will 10 workers take to complete the same job?