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 numbers that are less than
62​

Answer 1

0.889

Explanation:

I think it is multiplied.

10 *9 = 90

which is the total number of ways you can draw 2 cards without replacement.

I think it is easier to figure out how many possibilities there are over 62 and go from there.

10*9

10*8

10*7

===========

9*8

9*7

So there are 5 combinations that are over 62. There are 5 more possibilities because you could draw them in the reverse order

9 * 10

8 * 10

7 * 10

8* 9

7 * 9

In all there are 10 ways of drawing numbers that are over 62

So what is the probability of drawing 2 cards above 62?

10/90 = 1/9 = 0.111

Therefore, there must be a probability of 1 - 0.111 for under 62 = 0.889