How Likely Is It?

Mathematics · Probability · ages 9-10

Name ______________________ Date ____________

A bag holds 10 balls. How many of them must be red for picking a red ball to be certain?
Answer: ______________
A bag has 6 red, 3 blue, and 1 yellow ball. Which word best describes picking yellow?
- Certain
- Likely
- Unlikely
- Even chance
Rolling an even number on a fair die is an even chance.
Circle one: True False
A normal six-sided die is rolled. Which word describes rolling a 7?
- Certain
- Even chance
- Impossible
A jar has 5 blue marbles and 5 red marbles. What are the chances of pulling a red marble?
- Likely
- Unlikely
- Even chance
Order these from least likely to most likely: rolling 9 on a normal die (rolling 9), picking blue from a bag of 1 blue and 5 green balls (blue), flipping heads on a fair coin (heads), and picking green from that same bag (green).
- Blue, rolling 9, heads, green
- Rolling 9, blue, heads, green
- Rolling 9, heads, green, blue
A bag has 1 red ball and 9 blue balls. Which word best describes picking red?
- Certain
- Likely
- Unlikely
- Impossible
A bag contains only red and blue balls. Which word describes picking a green ball?
- Impossible
- Unlikely
- Likely
- Certain
Leo has 1 ticket out of 100 in a raffle. He says, 'I am certain to win.' What is wrong with what Leo said?
- Nothing, he really is certain to win
- Winning is likely, not certain
- Winning is unlikely, not certain
A bag has 4 red, 2 blue, and 2 green balls. Mia says picking red is likely, because red is the biggest colour group. Which word fits picking red?
- Likely, because red is the biggest group
- Even chance, because half the balls are red
- Unlikely, because most of the balls are not red

Answer key

For grown-ups. Fold this page away before handing over the rest.

How Likely Is It? W1-mt_iFFKZd-Vgv-s1

10 · Certain means it happens every time. If even one ball were not red, that ball could be picked. So all 10 balls must be red.
Unlikely · Only 1 of the 10 balls is yellow, so picking yellow is unlikely. It can still happen.
True · The even results are 2, 4, and 6. Three of the six die results are even, so the chance is one half.
Impossible · A normal die only shows numbers 1 to 6, so a 7 can never come up. That makes it impossible.
Even chance · There are the same number of red and blue marbles, so pulling red is an even chance.
Rolling 9, blue, heads, green · Rolling 9 is impossible. Blue is 1 ball out of 6, so it is unlikely. Heads is an even chance. Green is 5 balls out of 6, so it is likely. The order is rolling 9, blue, heads, green.
Unlikely · Red is possible but has only 1 chance out of 10, so picking red is unlikely.
Impossible · There are no green balls in the bag, so picking green cannot happen. It is impossible.
Winning is unlikely, not certain · With only 1 ticket out of 100, winning could happen but probably will not, so it is unlikely, not certain.
Even chance, because half the balls are red · There are 8 balls and 4 are red. That is half the bag, so picking red is an even chance. Likely would need more than half of the balls to be red.