A class has 21 girls and 12 boys. what is the probability that a boy's name is drawn at random

There are a total of 33 students in the class (21+12=33). There are 12 boys in the class so the chance of drawing a boys name would be 12/33 which reduces to 4/11. This means you will draw a boys name 4 times for every 11 draws. To find the percent probability, just divide ...

4/11 =.3636

multiply by 100 to convert to a percentage (move decimal to the right 2 places).

.3636 = 36.36%

There is a 36.36% chance that a boys name is drawn.

The probability that a boy name's drawn is 12/33 because if you add 21 and 21 you get 33 and you just put the 12 on top of the 33 with a slash.