I am way stumped. I know how to find combinations, but I have no clue how to find them with the combination given.
To furnish a room, a decorator is to select 2 chairs and 2 tables from a collection in a warehouse that are all different from each other. If there are 5 chairs in the warehouse, and 150 different combinations are possible. How many tables are in the warehouse?
The correct answer is 6, but I can't figure out how to get there. I can't even seem to plug in the correct answer to my calculations to reach the number 150.
I now understand the values to the left of the first equal sign. The rest looks like japanese to me. I understand both of the numerators, but I can't understand why the first fraction's denominator is 2! * 3!, nor why there is (n-2) in the second fraction's denominator.
So unfortunately, I do not have a textbook, lecture notes, or an instructor to consult, which leads me here to the Math Help Forum. For help with math. And if consulting you kind people here helps me significantly in my endeavor, I also intend to donate heavily in appreciation. Are you still willing to answer my questions on this particular problem so I can increase my understanding? Because the tone I received from you makes me feel unwelcome to ask for more help.