Find the total number of ways to select at least one red ball from a bag containing $4$ red balls and $3$ green balls, balls of the same colour being identical, if any number of balls may be selected.
For each selection of at least one red ball, green balls can be selected in $4$ ways, i.e. $\{0,1,2,3\}$ number of green balls selected. The answer should be $4 \times 4 = 16$.
But the answer given is $8$.
What am I missing?