How can you find the probability of a simple event if the total number of equally likely outcomes is 20?

Can someone me with this problem i don't understand i need

Me, the vertices of quadrilateral coat are c(2,0), o(7,0), a(7,2) and t(2,2). prove that coat is a rectangle.

If the value of x increases by 5, how does the value of m(x + 3) change? a) it increases by 5m. b) it increases by 8m. c) it decreases by 5m. d) it decreases by 8m.