8 is the answer, though I think you could cram the extra ten people into the seventh bus and not hire the eighth one
4×2=8 so n=2 and 8+12=20 so ?=12
Answer:
There are ten possible digits (0 to 9).
If they can be repeated, you're looking at 10 * 10 *10 * 10 * 10, or 105
This means 100000 possible zip codes if repeatable.
If not, you're looking at one less each time:
10 * 9 * 8 * 7 * 6
90 * 56 * 6
540 * 56 = 30240 zip codes without any repetitions.
Diameter= approx. 50.27
Circumference= approx. 25.13