Practice Test GeeksAMC 8 - American Mathematics Competition 8 Practice Test
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Probability & Counting Flashcards

6 cards from real AMC 8 practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 6 Probability & Counting flashcards as text

  1. If A and B are independent with P(A) = 0.3 and P(B) = 0.5, what is P(A and B)?

    Answer: 0.15

    For independent events, P(A and B) = P(A) × P(B) = 0.3 × 0.5 = 0.15.

  2. How many diagonals does a hexagon have?

    Answer: 9

    Using the formula n(n−3)/2: 6(6−3)/2 = 6 × 3/2 = 9 diagonals.

  3. A box has 6 red and 4 blue balls. Two balls are drawn without replacement. What is the probability both are red?

    Answer: 1/3

    P = (6/10) × (5/9) = 30/90 = 1/3.

  4. In how many ways can 3 people be seated in a row of 5 chairs?

    Answer: 60

    P(5,3) = 5 × 4 × 3 = 60.

  5. A number is chosen at random from 1 to 20. What is the probability it is divisible by 3 or 5?

    Answer: 9/20

    By inclusion-exclusion: 6 multiples of 3, plus 4 multiples of 5, minus 1 multiple of 15 = 9, so P = 9/20.

  6. How many distinct arrangements are there of the letters in the word LEVEL?

    Answer: 30

    LEVEL has 5 letters with L repeated twice and E repeated twice: 5!/(2! × 2!) = 120/4 = 30.