In a pizza restaurant, you get a basic pizza with two toppings, cheese and…
2024
In a pizza restaurant, you get a basic pizza with two toppings, cheese and tomato. You can also make up your own pizza with extra toppings. You can also choose from 10 different toppings, e.g. olives, ham, mushroom, salami etc. Ross wants to order a pizza with 2 different extra toppings. How many different combinations are possible?
- A.
100
- B.
200
- C.
90
- D.
45
Attempted by 564 students.
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Correct answer: D
We need the number of ways to choose 2 different extra toppings from 10 available.
The basic pizza already has cheese and tomato; these are not part of the 10 extra toppings.
Order does not matter when choosing toppings, so use combinations.
Formula: C(n,2) = n(n-1)/2
Substitute n = 10: C(10,2) = 10×9/2 = 45
Therefore there are 45 different combinations of 2 extra toppings.