Chance of "this or that": overlapping and mutually exclusive events

Answer Key - Grade 8 Math Worksheet

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

1. 1.

   Ari's jar holds 12 marbles: 3 red, 5 blue and the rest green. Ari picks one at random. In simplest form, what is the chance it is the first kind or the second?

   2/3
2. 2.

   Bo has 10 cards: 4 yellow, 2 green and the rest white. Bo picks one at random. In simplest form, what is the chance it is the first kind or the second?

   3/5
3. 3.

   Esme's bag holds 16 tiles: 2 star, 6 moon, the rest plain. Esme picks one at random. In simplest form, what is the chance it is the first kind or the second?

   1/2
5. 4.

   In the Venn picture, how many students take Art or Music, Jun?

   • 19
   • 16
   • 22
6. 5.

   In the Venn picture, what is the chance a student picked at random takes Art or Music, Kira?

   Use the picture in question 4.

   • 22/25
   • 19/25
   • 3/25
7. 6.

   Which pair of events can happen together on one roll of Milo's number cube?

   • Rolling a 1 and rolling a 2
   • Rolling an even and rolling over 4
   • Rolling an odd and rolling a 4 or a 6
8. 7.

   Noah picks one card numbered 1 to 10. For which pair may the two chances be added?

   • Drawing a 1 or drawing a 10
   • Drawing an even or drawing a 4
   • Drawing under 6 or drawing a 2
9. 8.

   Pia's spinner has 8 equal sections: 3 red, 2 blue, 3 green. What is the chance of red or blue?

   • 1/8
   • 5/8
   • 3/32
10. 9.

    Which is the full outcome list when Ren flips two coins?

    • HT, TH, HH
    • HH, HT, TH, TT
    • HH, HT, TT
11. 10.

    Zee rolls a fair number cube. What is the chance of a 2 or a number over 3?

    • 1/2
    • 1/12
    • 2/3