Tanvi packs 4 tops, 3 skirts and 2 pairs of shoes…
Contributed by StemPy LabTry it on paper first. A hint, the key idea and the worked solution are here when you need them.
Tanvi packs tops, skirts and pairs of shoes. An outfit is one top, one skirt and one pair of shoes. How many outfits can she wear? How many if she leaves one pair of shoes at home?
Need a reminder? The key ideaShow
If one event can happen in ways and, after it, a second event in ways, the two together can happen in ways. With repetition, each place keeps all its choices; without repetition, each place has one choice fewer than the one before.
The worked solution
Have you tried it?
Work it out on paper first. It is fine to get stuck or make a mistake: that is how we learn. When you are ready, go through the solution one step at a time, and check each step against your own.
Step 1. Three stages. Top: ways. Skirt: ways. Shoes: ways.
Step 2. Multiply. outfits.
Step 3. One pair of shoes. outfits.
Answer: outfits, and with one pair of shoes.
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