Answer:
455 or 680, depending
Step-by-step explanation:
If we assume the three choices are different, then there are ...
15C3 = 15·14·13/(3·2·1) = 35·13 = 455
ways to make the pizza.
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If two or three of the topping choices can be the same, then there are an additional ...
2(15C2) +15C1 = 2·105 +15 = 225
ways to make the pizza, for a total of ...
455 + 225 = 680
different types of pizza.
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There is a factor of 2 attached to the number of choices of 2 toppings, because you can have double anchovies and tomato, or double tomato and anchovies, for example, when your choice of two toppings is anchovies and tomato.
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nCk = n!/(k!(n-k)!)
Answer:
B. (1/2, 3)
Step-by-step explanation:
It is perhaps easiest to try the point values in the equations.
A — 4·2+1 = 9; -2·2 +4 ≠9 . . . . not the answer
B — 4·1/2 +1 = 3; -2·(1/2) +4 = 3 . . . . this is the answer
we need go no further since we have the answer
Maury = 120/10 (12 calls/hour)
Tyra = 120/8 (15 calls/hour)
Together they are 27 calls per hour.
120 / 27 = 4.4444444444
So it'd take them 4.44444444 (recurring) hours to make 120 calls.