1)I have 5 different pullover shirts and 4 different button-down shirts. In how many ways can I choose shirts for the next 9 days if I insist on wearing pullover shirts two days in a row at least once? Assume that I wear one shirt each day, and every shirt gets worn once.

2)How many different non-congruent isosceles triangles can be formed by connecting three of the dots in a 4x4 square array of dots like the one shown below?

Picture: https://latex.artofproblemsolving.com/c/b/0/cb06885af853019aa03cd8d3d48f31d63144e6c3.png

FiestyGeco
Jun 16, 2018

#1**+1 **

**2)**

**How many different non-congruent isosceles triangles can be formed by connecting three of the dots in a 4x4 square array of dots like the one shown below?**

**Picture: https://latex.artofproblemsolving.com/c/b/0/cb06885af853019aa03cd8d3d48f31d63144e6c3.png**

**see link:** https://web2.0calc.com/questions/please-help_50163

heureka
Jun 18, 2018