Question

Ten identical cards are numbered 1 to 10. The cards are shuffled. One card is selected at random. what is the probability that the number written on it is:

10?
5?
Not 10?
An Odd Number?
A number less than 4?
A number greater than 7?

Answer 1

To solve these, basically find out how many numbers satisfy your requirment, then divide that number by 10. Simplify your fraction and you have your probability.

probability of getting a 10: 1/10
probability of getting a 5: 1/10
probability of not getting 10: 9/10
probability of getting an odd number: 5/10
probability of getting a number less than 4: 3/10
probability of getting a number greater than 7: 3/10

Hope this helps, and muchas luck on your math!