Inductive: determine the pattern
deductive: to calculate the next term
and your problem looks like its deductive
The proportion equal to a/b = c/d is A.) A/C = B/D
We will know if a proportion is equivalent when its cross products are equal.
a/b = c/d where ad = bc
since ad = bc, a/c = b/d
Let w= number of weeks
400-40w<= 160
btw <= means less than or equal too