An experiment is given together with an event. Determine the (modeled) probability of each event, supposing that the coins (or dice) are distinguishable and fair, and that what is observed are the faces uppermost.
a) Four coins are tossed; the result is at most one tail.
b) Two dice are rolled; the numbers add to 5.
c)Two dice are rolled; the numbers add to 11.
d)Two dice are rolled; the numbers add to 13.
e) Two dice are rolled; both numbers are prime. (A positive integer is prime if it is neither 1 nor a product of smaller integers.)