Counting problems – practice for Years 7–9
Sample questions on Counting problems with the right answer and a worked solution, from easy to hard. In the Pickles Academy app a child gets new questions of the same kind every time, so they can't just learn the answers by heart.
- Subject
- Maths
- Year
- Years 7–9
- Curriculum area
- Problem solving and non-routine tasks
Question types: How many ways?
Rule: Counting problems
When you choose step by step, multiply the numbers of choices at each step.
Without repeats there is one choice fewer at the next step; a number can’t start with 0.
Example: Three-digit numbers from 5 digits without repeats: 5 × 4 × 3 = 60
Watch out: With pairs (handshakes) you count each one twice, so divide by 2: 10 × 9 ÷ 2 = 45.
Sample questions
-
Question 1 Easy
The canteen offers 5 soups and 5 main courses. How many different lunches of one soup and one main course can you choose?
Show the solution
Answer: 25How it works: Every first choice goes with every second choice: 5 × 5 = 25
-
Question 2 Normal
How many different two-digit numbers can be written with the digits 1, 5, 6, 8, 9 if no digit may be used twice?
Show the solution
Answer: 20How it works: The tens digit can be any of 5, the ones digit any of 4: 5 × 4 = 20
-
Question 3 Hard
How many different three-digit numbers can be written with the digits 1, 5, 6, 8, 9 if no digit may be used twice?
Show the solution
Answer: 60How it works: 5 × 4 × 3 = 60
Keep practising in the app
In a minute, your child has their own avatar and a first task. Free, no ads, data in the EU.
Start for free