Two-step chance: lists, tables and trees

Answer Key - Grade 7 Math Worksheet

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

1. 1.

   Esme rolls a fair number cube and flips a fair coin. What is the chance of a number 4 or greater and heads, in simplest form?

   1/4
2. 2.

   Jun spins a spinner with 3 equal parts (red, blue, yellow) and draws a card from 1 to 5 without looking. What is the chance of blue and an odd card, in simplest form?

   1/5
3. 3.

   Milo flips two fair coins. What is the chance of two heads, as a percent?

   25
4. 4.

   Ren rolls two fair number cubes. What is the chance that the sum is 3, in simplest form?

   1/18
5. 5.

   Tala rolls two fair number cubes. What is the chance that the sum is 9, in simplest form?

   1/9
6. 6.

   Ari flips two fair coins. What is the chance of exactly one head, in simplest form?

   1/2
7. 7.

   Bo flips two fair coins. What is the chance of at least one head, in simplest form?

   3/4
8. 8.

   Luz flips a fair coin and spins a spinner with 4 equal parts numbered 1 to 4. Which is the whole list of outcomes for both?

   • H1, H2, H3, H4, T1, T2, T3, T4
   • H1, H2, H3, H4
   • H1, H2, H3, H4, T1, T2, T3, T4, T5
   • H, T, 1, 2, 3, 4
9. 9.

   Milo spins a spinner with 2 equal parts (R, B), then one with 3 equal parts numbered 1 to 3. Which is the whole list of outcomes for both?

   • R1, R2, R3, B1, B2, B3, B4
   • R1, R2, R3
   • R1, R2, R3, B1, B2, B3
   • R, B, 1, 2, 3

10. Read this first

    Tree

    The card splits into red and blue; each of those splits into 1, 2, 3 and 4. Leaves: red-1, red-2, red-3, red-4, blue-1, blue-2, blue-3, blue-4.

11. 10.

    Pia picks 1 of 2 cards (1 red, 1 blue) without looking, then spins a spinner (1 to 4, equal parts). What is the chance of blue and a number over 2, in simplest form?

    1/4