4-

a. How many unique Plickers cards are possible (not considering rotation) if you want the code to be balanced. Which is to say: each value has the same number of 1's and 0's? (Note: the actual Plickers cards values are not balanced.)

b. How many more cards are possible if the code includes near balanced values? Which is to say, rather than an equal number of 1's and 0's, from an equal number there is an extra 1 or 0 in each value. (Hint: something similar is true for the 8-to-10 code.)