Answer:
First, let's find how many students there are in total:
11 girls + 9 boys
= 20 students.
Out of those 20 students, we are trying to find the probability if Natalia will be selected first.
There is only one <u>Natalia</u>.
So, out of those students, the probability of selecting Natalia is a:
<u>1/20 probability</u>
(if wanted to convert into a percentage):
1/20 x 100
= <u>5% probability</u>
<u></u>
Since we already know there are 28 given pens in total and 4 of them are red pens, there is a:
4/28 chance of selecting a red pen which can be simplified to a <u>1/7 probability.</u>
(if wanted to convert into a percentage):
1/7 x 100
= <u>14% probability</u>
<u></u>
Since we already know there are 24 jelly beans in total and 9 of them are cherry beans, there is a:
<u>9/24 chance/probability</u> of selecting a cherry jelly bean.
(if wanted to convert into a percentage):
9/24 x 100
= <u>37.5% probability</u>
<u></u>
Let's first figure out how many marbles there are in total.
2 + 3 + 7
= 12 marbles in total.
Now let's exclude the marbles that are blue and yellow, leaving us with 7 orange marbles.
So the probability of selecting a marble that isn't blue/yellow is a:
<u>7/12 probability</u>
(if wanted to convert into a percentage)
7/12 x 100
= <u>58% probability</u>