The answer could be expressed as 2^8 because the product is 16!
Is it necessary
Can I get it cheaper elsewhere
Will it last a while
These are just 3 I came up with. I do not know if they are what your teacher would have put.
I and III seem to be correct, II doesn't because, for example, if x = w = z = t = 70 and y = u = 40, then all three pairs of vertical angles in the figure have equal measure and the given condition x + y = u + w stands. But it means y is not equal to w.
The slope is 20/13. Yes, the slope is steeper because without the lip on the slide you would travel downward faster.