Two-step chance: lists, tables and trees

Answer Key - Grade 7 Math Worksheet - Building Confidence

Circle the best answer, or write your answer on the line.

1. 1.

   Ren's first spinner has 3 equal parts and the second has 2 equal parts. How many outcomes are in the list for both spinners?

   6
2. 2.

   Ari flips a fair coin and spins a spinner with 5 equal parts. How many outcomes are in the list for both?

   10
3. 3.

   H1, H2 ✓, H3, H4 ✓, T1, T2, T3, T4. Bo flips a fair coin and spins a spinner with 4 equal parts numbered 1 to 4. The checked cells show heads with an even number. What is the chance of that, in simplest form?

   1/4
4. 4.

   Kira flips a fair coin and rolls a fair number cube. The checked cells show tails with a 5 or a 6. What is the chance of that, in simplest form?

   1/6
5. 5.

   Luz flips a fair coin and spins a spinner with 3 equal parts. The checked branch shows tails and red. What is the chance of that, in simplest form?

   1/6

6. Read this first

   Tree

   The first spinner splits into star and moon; each of those splits into 1, 2, 3 and 4. Leaves: star-1 ✓, star-2, star-3 ✓, star-4, moon-1, moon-2, moon-3, moon-4.

7. 6.

   Milo spins two spinners with equal parts: one star/moon, one numbered 1 to 4. The checked branches show a star and an odd number. What is the chance of that, in simplest form?

   1/4
8. 7.

   Ren flips a fair coin twice. Which is the whole list of outcomes for the two flips?

   • H, T
   • HH, HT, TT
   • HH, HT, TH, TT
   • HH, TT
9. 8.

   Tala spins two spinners, each with 2 equal parts: red (R) and blue (B). Which is the whole list of outcomes for both spinners?

   • RR, BB
   • RR, RB, BB
   • RR, RB, BR, BB
   • R, B
10. 9.

    Zee flips a fair coin and spins a spinner with 3 equal parts: red, blue, green. Which is the whole list of outcomes for both?

    • H-red, H-blue, H-green, T-red, T-blue, T-green, T-yellow
    • H-red, H-blue, H-green
    • H-red, H-blue, H-green, T-red, T-blue, T-green
    • H, T, red, blue, green
11. 10.

    Ari spins a spinner with 3 equal parts (A, B, C), then one with 2 equal parts (1, 2). Which is the whole list of outcomes for both?

    • A, B, C, 1, 2
    • A1, B2, C1
    • A1, A2, B1, B2, C1, C2
    • A1, A2, B1, B2, C1, C2, D1