Question

A taco stand sells tacos with any three ingredients for a flat price of $1.25. Additional ingredients cost $0.50 each. There are ten different possible ingredients. How many different types of tacos costing $2.25 can be made at the stand?
A. 160
B. 252
C. 345
D. 452
E. 610

Answer 1

to cost $2.25 there must have been 5 ingredients on each of the tacos.
number of ways to choose 5 from 10
= C(10,5) = 252