Question 1156227
Suppose that 21 slips of paper numbered 1 to 21, inclusive, are put into a hat.
Then one slip is drawn out of the hat.

1. Find the probability that the slip with a 4 is drawn.<pre> Well let's see. We have 21 slips of paper with these numbers written on them:

1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21

How many have 4 on them?  I'll color any that have 4 on them red.

1,2,3,<font color="red"><b>4</b></font>,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21

How many did I color red? Just 1.  So that's 1 out of 21.  
So the probability is 1/21.</pre>2. Find the probability that a slip with an even number on it is drawn.<pre>How many have an even number on them?  I'll color any that have an even number
on them red.

1,<font color="red"><b>2</b></font>,3,<font color="red"><b>4</b></font>,5,<font color="red"><b>6</b></font>,7,<font color="red"><b>8</b></font>,9,<font color="red"><b>10</b></font>,11,<font color="red"><b>12</b></font>,13,<font color="red"><b>14</b></font>,15,<font color="red"><b>16</b></font>,17,<font color="red"><b>18</b></font>,19,<font color="red"><b>20</b></font>,21

How many did I color red? I count 10.  That's 10 out of 21.  
So the probability is 10/21.</pre>3. Find the probability that a slip with a multiple of five on it is drawn.<pre>How many have a multiple of 5 
on them?  I'll color any that have a multiple of 5 on them red.

1,2,3,4,<font color="red"><b>5</b></font>,6,7,8,9,<font color="red"><b>10</b></font>,11,12,13,14,<font 
color="red"><b>15</b></font>,16,17,18,19,<font color="red"><b>20</b></font>,21

How many did I color red? I count 4.  That's 4 out of 21.  
So the probability is 4/21. 

This was very easy, wasn't it?

Edwin</pre>