Unit 4 · Statistics and Probability
Jason's Outfit Combinations — Counting Arrangements
Lesson 1 of 8
Outfit counting = trousers × shirts. Calculate each person’s total, then subtract to find the difference.
Multiplication counting principle questions appear in the very easy band of Selective MR. They’re quick marks when you multiply correctly, but students who add instead of multiply will get a wrong total and compare incorrectly.
The examiner checks whether students (1) multiply (not add) trousers × shirts for each person and (2) correctly compare 12 and 10 to determine who has more and by how much.
Two people have different numbers of clothing items. Students calculate the number of outfit combinations for each and compare them.
Best approach: Jason: 3 × 4 = 12 outfits. Emily: 2 × 5 = 10 outfits. 12 − 10 = 2. Jason has 2 more outfits.
Question
Jason has 3 different pairs of trousers and 4 different shirts.
Emily has 2 different pairs of trousers and 5 different shirts.
Each person can make an outfit from their own clothes by choosing 1 pair of trousers and 1 shirt.
Who has a larger number of possible outfits, and by how many?
Select an answer to see the explanation.
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