Three cards are chosen from seven cards of different colors. The red card must be included, and the blue card must not be included. How many different sets can be made?
Show hints
- One card has already been selected, one cannot be chosen.
- How many ways can there be to choose two of the remaining five?
Show the answer and solution
Answer: 10
Red has already been selected, blue has been excluded. Of the five remaining, we choose two: 5 × 4 ÷ 2 = 10.