Practice Test GeeksIMO - International Mathematics Olympiad Practice Test
← All IMO Flashcard Decks

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. A number leaves a remainder of 3 when divided by 7. Which could be the number?

    Answer: 24

    24 ÷ 7 = 3 remainder 3, so 24 leaves a remainder of 3 when divided by 7.

  2. What is the sum of all prime numbers less than 10?

    Answer: 17

    Primes less than 10 are 2, 3, 5, 7; their sum = 2 + 3 + 5 + 7 = 17.

  3. What is the LCM of 6, 8, and 12?

    Answer: 24

    LCM(6, 8, 12) = 24, since 24 is the smallest number divisible by all three.

  4. Which statement is true about the number 1?

    Answer: It is neither prime nor composite

    1 is neither prime nor composite by mathematical definition, as prime numbers must have exactly two distinct factors.

  5. What is 3⁴?

    Answer: 81

    3⁴ = 3 × 3 × 3 × 3 = 81.

  6. Two numbers have an HCF of 5 and an LCM of 60. If one number is 15, what is the other?

    Answer: 20

    Product of numbers = HCF × LCM = 5 × 60 = 300; other number = 300 ÷ 15 = 20.

How this page was made: written with AI tools and published by Nathan Beja, founder of Practice Test Geeks, who is responsible for its content. Exam facts are checked against the official sources listed below. Not reviewed by a subject-matter expert. Editorial policy

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