Practice Test GeeksIMO - International Mathematics Olympiad Practice Test
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Number Theory Flashcards

6 cards from real IMO practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 6 Number Theory flashcards as text

  1. Which of the following numbers is a prime number?

    Answer: 29

    29 is prime because it has no divisors other than 1 and itself.

  2. What is the LCM of 4 and 6?

    Answer: 12

    The Least Common Multiple of 4 and 6 is 12, the smallest number both divide evenly.

  3. What is the HCF (GCD) of 18 and 24?

    Answer: 6

    The Highest Common Factor of 18 and 24 is 6, as 6 is the largest number that divides both.

  4. Which of the following is a composite number?

    Answer: 15

    15 = 3 × 5, so it is composite because it has factors other than 1 and itself.

  5. What are the prime factors of 36?

    Answer: 2 and 3

    36 = 2² × 3², so its prime factors are 2 and 3.

  6. Which of the following numbers is divisible by both 3 and 4?

    Answer: 24

    24 ÷ 3 = 8 and 24 ÷ 4 = 6, so 24 is divisible by both 3 and 4.

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Sources & references

Exam facts on this page (fees, format, dates, passing scores) are checked against these official sources; the date is our last check. Editorial policy

  1. imo-official.org — Test delivery, eligibility, passing score, test dates, exam format · verified Oct 2026
  2. imo2027.hu — Exam dates, registration deadline · verified Oct 2026