Seven sticks with lengths 2, 3, 5, 7, 11, 13 and 17 inches are placed in a box. Three of the sticks are randomly selected. What is the probability that a triangle can be formed by joining the endpoints of the sticks? Express your answer as a common fraction

Respuesta :

Answer: 9/35

Step-by-step explanation:

lengths: 2, 3, 5, 7, 11, 13, 17

triangle can be formed only if the sum of 2 sides is bigger than the other side.

Pick 3 randomly

It's not ordered

Total: ā‚ƒCā‚‡ = 35

That form a triangle:

No triangle can be formed with the 2 inches stick.

triangles possible: 3, 5, 7 | 3, 11, 13 | 5, 7, 11 | 5, 11, 13 | 5, 13, 17 | 7, 11, 13 | 7, 11, 17| 7, 13, 17 | 11, 13, 17

Total: 9

prob = 9/35