Probability Short Problems - Age 14-16
Flipping Coins
A coin is flipped 4 times. What is the probability of getting heads at least 3 times?
Collecting Marbles
How many marbles need to be taken out to ensure that at least three are of the same colour?
Tying the Rope
What is the probability that two pieces of rope are tied together, when Pat ties two loose ends together?
Swapping Sweets
If two girls each take a sweet from each other's bags, what is the probability that they end up with what they started with?
One or Both
Problem 1 was solved by 70% of the pupils. Problem 2 was solved by 60% of them. Can you work out how many pupils took the exam?
XOXOXO
6 tiles are placed in a row. What is the probability that no two adjacent tiles have the same letter on them?
Odd Dice
These strange dice are rolled. What is the probability that the sum obtained is an odd number?
Switch On
In how many different ways can a row of five "on/off" switches be set so that no two adjacent switches are in the "off" position?
CD Collection
How many different ways can I arrange the CDs in my collection?
Takeaway Time
Pizza, Indian or Chinese takeaway? If everyone liked at least one, how many only liked Indian?
Vegtown Elections
What percentage of people voted for the Broccoli party in the Vegtown election?
Descending Deal
Four cards from a set numbered 1-36 are dealt. What is the probability that they are dealt in order?
Counting Kangaroos
Can you work out how many kangaroos Rachel draws in one colour?
Two Girls
There are 10 girls in a mixed class. If two pupils are selected, the probability that they are both girls is 0.15. How many boys are in the class?
Different Digital Clock
At how many times between 10 and 11 o'clock are all six digits on a digital clock different?
Numbers or Letters?
Which game offers you the best chance of winning?
Phone Call
How many different phone numbers are there starting with a 3 and with at most two different digits?
Dropouts
What percentage of students who graduate have never been to France?
Medal Ceremony
The teacher has forgotten which pupil won which medal. In how many different ways could he give the medals out to the pupils?
Domino Match
If you take two dominoes from a set at random, what is the probability that they 'match'?