The numbers $3,4,5,6,7,8,9,10,11,12,13$ are written on separate cards and placed face down on a table. A card is chosen at random and flipped over. What is the probability that the number on this card is a prime number?
(A) $\frac{2}{11}$
(B) $\frac{4}{11}$
(C) $\frac{6}{11}$
(D) $\frac{3}{11}$
(E) $\frac{5}{11}$

## Part B: Each correct answer is worth 6.
Of the given 11 numbers, the numbers $3,5,7,11$ and 13 are prime. $(4,6,8,10$ and 12 are not prime, since they are divisible by 2 , and 9 is not prime since it is divisible by 3 .)

Therefore, 5 of the 11 numbers are prime.

Thus, if a card is chosen at random and flipped over, the probability that the number on this card is a prime number is $\frac{5}{11}$.

ANSWER: (E)