Worked example
A bag has 2 red and 3 blue counters. One is selected without looking, with each counter equally likely. What is the probability of red?
Answer & why
Answer:
There are 2 red counters among 5 equally likely counters.
Grade 7 · Math
Find a simple probability
Represent favorable outcomes as a fraction of equally likely outcomes.
8 generated examples + worked example
Add to plan
Try these examples
8 reproducible examples from this math generator. Choose New examples for another set.
Question 1
A bag contains 1 red counters and 6 blue counters. One counter is selected without looking, with each counter equally likely. What is the probability of red in simplest form?
A hint
Probability is favorable equally likely outcomes divided by all outcomes.
Answer & why
Answer:
1 favorable counters out of 7 total gives , which simplifies to 1/7.
Question 2
A bag contains 2 red counters and 4 blue counters. One counter is selected without looking, with each counter equally likely. What is the probability of red in simplest form?
A hint
Probability is favorable equally likely outcomes divided by all outcomes.
Answer & why
Answer:
2 favorable counters out of 6 total gives , which simplifies to 1/3.
Question 3
A bag contains 5 red counters and 3 blue counters. One counter is selected without looking, with each counter equally likely. What is the probability of red in simplest form?
A hint
Probability is favorable equally likely outcomes divided by all outcomes.
Answer & why
Answer:
5 favorable counters out of 8 total gives , which simplifies to 5/8.
Question 4
A bag contains 6 red counters and 4 blue counters. One counter is selected without looking, with each counter equally likely. What is the probability of red in simplest form?
A hint
Probability is favorable equally likely outcomes divided by all outcomes.
Answer & why
Answer:
6 favorable counters out of 10 total gives , which simplifies to 3/5.
Question 5
A bag contains 6 red counters and 2 blue counters. One counter is selected without looking, with each counter equally likely. What is the probability of red in simplest form?
A hint
Probability is favorable equally likely outcomes divided by all outcomes.
Answer & why
Answer:
6 favorable counters out of 8 total gives , which simplifies to 3/4.
Question 6
A bag contains 5 red counters and 6 blue counters. One counter is selected without looking, with each counter equally likely. What is the probability of red in simplest form?
A hint
Probability is favorable equally likely outcomes divided by all outcomes.
Answer & why
Answer:
5 favorable counters out of 11 total gives , which simplifies to 5/11.
Question 7
A bag contains 2 red counters and 3 blue counters. One counter is selected without looking, with each counter equally likely. What is the probability of red in simplest form?
A hint
Probability is favorable equally likely outcomes divided by all outcomes.
Answer & why
Answer:
2 favorable counters out of 5 total gives , which simplifies to 2/5.
Question 8
A bag contains 6 red counters and 6 blue counters. One counter is selected without looking, with each counter equally likely. What is the probability of red in simplest form?
A hint
Probability is favorable equally likely outcomes divided by all outcomes.
Answer & why
Answer:
6 favorable counters out of 12 total gives , which simplifies to 1/2.