For which pair of functions does f(g(x))=g(f(x))=x

The box plot shows the number of raisins found in sample boxes from brand c and from brand d. each box weighs the same. what could you infer by comparing the range of the data for each brand? a) a box of raisins from either brand has about 28 raisins. b) the number of raisins in boxes from brand c varies more than boxes from brand d. c) the number of raisins in boxes from brand d varies more than boxes from brand c. d) the number of raisins in boxes from either brand varies about the same.

Can someone me out here number 4 plz

Richard save $32 in march he saved $48 in april and $38 in may then richard spent $113 on a keyboard how much money does richard have left