### Home > A2C > Chapter Ch10 > Lesson 10.2.3 > Problem 10-96

10-96.

'No three are colinear' means that any line drawn through two of the points will not intersect any of the other 5 points.

In order for a line to be determined by these points, it must pass through at least two of them.

Write a statement in the form of * _{n}*C

*to describe the situation.*

_{r}Write a statement to describe choosing 3 out of the 7 points.

_{7}C_{3} = 35

Write a statement to describe choosing 4 out of the 7 points.

Write the answers to parts (b) and (c) in * _{n}*C

*form, and then in factorial form.*

_{r}Instead of simplifying, look at the similarities between the expressions.