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

Answer Key - Grade 8 Math Worksheet - Building Confidence

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

1. 1.

   Ari's bag holds 8 counters, and 3 of them are red. Ari picks one at random. In simplest form, what is the chance it is NOT that kind?

   5/8
2. 2.

   Jun rolls a number cube. Which list shows every outcome for 'an even number'?

   • 1, 3, 5
   • 2, 4, 6
   • 2, 4
3. 3.

   Kira rolls a fair number cube. What is the chance of a 5 or a 6?

   • 1/6
   • 1/36
   • 1/3
4. 4.

   Luz picks one card at random from cards 1 to 10. What is the chance of a 3 or an 8?

   • 1/100
   • 1/10
   • 1/5
5. 5.

   The forecast gives Milo's town a 0.3 chance of rain. What is the chance of no rain?

   • 0.3
   • 1.3
   • 0.7
6. 6.

   Noah adds the chance of an event and the chance of its opposite. What is the total?

   • 1/2
   • 0
   • 1
7. 7.

   What is the opposite of 'rolling a 6' on Pia's number cube?

   • Rolling a 6 again
   • Rolling a 1
   • Rolling 1, 2, 3, 4 or 5
8. 8.

   Which pair of events cannot happen on the same roll of Ren's number cube?

   • Rolling a 1 and rolling a 6
   • Rolling under 3 and rolling a 2
   • Rolling an even and rolling a 4
9. 9.

   Tala pulls one sock, and each sock is one color. Can that sock be both red and blue?

   • Yes, half of the time
   • No, one sock has one color
   • Yes, if the chances add up
10. 10.

    What does the overlap of two circles in a Venn picture show Zee?

    • Outcomes in just one event
    • Outcomes in both events
    • Outcomes in neither event