Question

A triangle has one side that is 5 inches long and another side that is 7 inches long. The last side of the triangle is a whole number of inches long. How many different lengths, in inches, are possible for the last side of the triangle?

A
2

B
4

C
9

D
11

Answer 1

C. 9

Because it must fall within the range below. 

3<x<13

This is due to the fact that two sides added together must always be greater than the 3rd side.