IMO Arithmetic and Operations 2 — Questions and Answers
Question 1: What is the result of 5/8 + 3/8?
- 7/8
- 1 (Correct answer)
- 15/64
- 8/16
Correct answer: 1
5/8 + 3/8 = 8/8 = 1.
Question 2: Which of the following is the greatest: 3/4, 5/8, 7/10, or 2/3?
- 3/4 (Correct answer)
- 5/8
- 7/10
- 2/3
Correct answer: 3/4
Converting to decimals: 3/4 = 0.75, 5/8 = 0.625, 7/10 = 0.70, 2/3 ≈ 0.667; so 3/4 is greatest.
Question 3: What is 2.5 × 4.2?
- 8.5
- 9.5
- 10.5 (Correct answer)
- 11.5
Correct answer: 10.5
2.5 × 4.2 = 10.5.
Question 4: A student scored 72 out of 90. What percentage did they score?
- 75%
- 78%
- 80% (Correct answer)
- 82%
Correct answer: 80%
Percentage = (72/90) × 100 = 80%.
Question 5: What is the value of 7! (7 factorial)?
- 1024
- 2520
- 4320
- 5040 (Correct answer)
Correct answer: 5040
7! = 7 × 6 × 5 × 4 × 3 × 2 × 1 = 5040.
Question 6: If a train covers 3/5 of a journey in 3 hours, how long will the full journey take?
- 4 hours
- 5 hours (Correct answer)
- 6 hours
- 7 hours
Correct answer: 5 hours
If 3/5 takes 3 hours, the full journey = 3 ÷ (3/5) = 3 × 5/3 = 5 hours.
IMO Arithmetic and Operations 2
What is the result of 5/8 + 3/8?