christinadianex christinadianex
  • 18-07-2017
  • Mathematics
contestada

A test consists of 20 problems and students are told to answer any 15 of these questions. In how many different ways can they choose the 15 questions?

Respuesta :

adud adud
  • 18-07-2017
1 - 15
2 - 17
3 - 18
4 - 19
5 - 20
Answer Link
irspow
irspow irspow
  • 18-07-2017
Since order is not important, we are looking for unique combinations. For this type of problem you use the "n choose k" equation.

n!/(k!(n-k)!), where n=total amount of choices, k=number of choices made.

In this case:

20!/(15!(20-15)!)

20!/(15!*5!)

15504
Answer Link

Otras preguntas

Please help:) Thank u so much !
what is x in this problem 8-(-4)^2-5=x
Someone please help me with this :/ 5.Express the number 0.307 x 10-Bin scientific notation, A 3.07 x 10-9 B 3.07 x 10-6 3.07 x 10-1 3.07 x 10-8
How many years to liberate the South?
how many articles or divisions are there in the U.S constitution
In the blank controversy ,church and state leaders argued over whether icons should be allowed in worship
Which of the following best illustrates the concept of limited government?
What is the vertex of this absolute value function?
Which river is located in Africa and is the world's longest river, at 4.160 miles? A. the Amazon River B. the Congo River C. the Niger River D. the Nile River​
Dr. Comeaux decides to conduct a survey of her class to determine whether the number of breaks is sufficient for a three-hour class period. She assigns each of