Tonya and Lauren are designing a soccer uniform. They want to use two colors on the shirt. their choices are green, orange, yellow, purple, blue and silver. How many ways can they choose two colors?

There are 15 different colour combinations that Tonya and Lauren can choose. These are listed as follows:

Green Orange, Green Yellow, Green Purple, Green Blue, Green Silver - 5

Orange Yellow, Orange Purple, Orange Blue, Orange Silver - 4

Yellow Purple, Yellow Blue, Yellow Silver - 3

Purple Blue, Purple Silver - 2

Blue Silver - 1