Question

10 cards are numbered from 1 to 10 and placed in a box. One card is selected at random and is not replaced. Another card is then randomly selected. What is the probability of selecting two prime numbers?

Answer 1

First you need to know the prime numbers from 1-10.
They are 2, 3, 5, 7,
1st draw: P(prime) = 4/10
2nd draw: P(prime) = 3/9
Multiply these numbers 12/90 = 2/15