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.

   Tala flips a fair coin and rolls a fair number cube (a busy afternoon). How many outcomes are in the list for both?

   12
2. 2.

   Zee picks one of 4 shirts and one of 5 hats for picture day, and every pair is allowed. How many different outfits are possible?

   20
3. 3.

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

   10
4. 4.

   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
5. 5.

   HH ✓, HT ✓, TH ✓, TT. Jun flips a fair coin twice (the coin does not mind). The checked cells show at least one head. What is the chance of that, in simplest form?

   3/4
6. 6.

   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
7. 7.

   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

8. Read this first

   Tree

   The spinner splits into red and blue; each of those splits into H and T. Leaves: red-H ✓, red-T, blue-H, blue-T.

9. 8.

   Pia spins a spinner with 2 equal parts (red, blue), then flips a fair coin. The checked branch shows red and heads. What is the chance of that, in simplest form?

   1/4
10. 9.

    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
11. 10.

    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