Two-step chance: lists, tables and trees

Answer Key - Grade 7 Math Worksheet - Challenge Me

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

1. 1.

   Zee rolls two fair number cubes. What is the chance of at least one 6, in simplest form?

   11/36
2. 2.

   Ari spins two spinners, each with 4 equal parts numbered 1 to 4. What is the chance of at least one 4, in simplest form?

   7/16
3. 3.

   Bo flips a fair coin four times (a tired thumb is expected). What is the chance of at least one tail, in simplest form?

   15/16
4. 4.

   A bag holds 4 different buttons. Esme draws one, keeps it out, then draws a second. How many outcomes are in the list of the two draws, with order counting?

   12
5. 5.

   Kira has 6 different star stickers and picks one, sets it aside, then picks a second. How many outcomes are in the list of the two picks, with order counting?

   30
6. 6.

   A bag holds 2 red buttons and 2 blue buttons. Luz draws one without looking, keeps it out, then draws a second. What is the chance both are red, in simplest form?

   1/6
7. 7.

   A bag holds 3 red buttons and 3 blue buttons. Noah draws one without looking, keeps it out, then draws a second. What is the chance both are blue, in simplest form?

   1/5
8. 8.

   Pia flips a fair coin twice and then spins a spinner with 3 equal parts. How many outcomes are in the list for all three steps?

   12
9. 9.

   Ren rolls a fair number cube and then flips a fair coin twice. How many outcomes are in the list for all three steps?

   24
10. 10.

    Ari spins two spinners, each with 5 equal parts numbered 1 to 5. What is the chance that the sum is 7, as a percent?

    16