Probability of a single event
The Maths Habit
A spinner has 4 equal sections:
Likely
3 yellow and 1 green. It is spun once.
How likely is it to land on yellow?A card is picked from cards numbered 1 to 20. How likely is it to be a number less than 30?
CertainA bag holds 6 pink and 6 white beads. One bead is picked. How likely is it to be white?
Even chance
You win if you pick a red counter.
Bag A: 1 red and 1 blue.
Bag B: 3 red and 5 blue.
Which bag would you pick from?
Bag A: half of it is red, and less than half of bag B is
- Probability
- How likely something is, from 0 (impossible) to 1 (certain).
A bag holds 2 red and 6 blue counters. One is taken at random. Find P(red).
A bag holds 5 green and 4 yellow counters. One is taken at random. Find P(yellow).
A bag holds 2 red and 6 blue counters. One is taken at random. Find P(red).
A bag holds 3 red, 3 blue and 4 green counters. One is taken at random. Find P(green).
A bag holds 2 red and 6 blue counters. One is taken at random. Find P(red).
A bag holds 6 yellow and 3 green counters. One is taken at random. Find P(yellow).
A bag holds 2 red and 6 blue counters. One is taken at random. Find P(red).
A bag holds 2 green, 3 red and 5 blue counters. One is taken at random. Find P(not red).
A bag holds 2 red and 6 blue counters. One is taken at random. Find P(red).
A bag holds 3 blue, 1 red and 5 green counters. One is taken at random. Find P(blue).
Answer sheet
A bag holds red and blue counters. P(red) = 37. There are 9 red counters. How many are blue?
12A spinner has 8 equal sections. P(red) = 14. How many sections are red?
2A bag holds 6 purple, 2 orange and 4 white counters. One is taken at random. Find P(not orange).
1012 = 56
A bag holds 5 red and 6 blue counters. One is taken at random. Find P(red).
511A bag holds 3 red, 4 blue and 2 white counters. One is taken at random. Find P(not blue).
59A bag holds 4 green counters and some yellow counters. P(green) = 13. How many yellow counters are there?
8