Question

A marble is selected at random from a jar containing 5 red marbles, 2 yellow marbles & 3 green marbles. What is the probability that a)the marble is red
b)the marble is not yellow
c)the marble is either red or green
d)the marble is neither red nor green

Answer 1

Answer:

5/11

explanation

Probability here is the chance of selection out of a total. So, we need to first find the total number of marbles.

total

=

5

+

3

+

2

+

1

=

11

So there are  

11

marbles total. The probability that we pick one of the  

3

green marbles out of the  

11

is simply that ratio:

P

green

=

3

11

Same idea for yellow:

P

yellow

=

2

11

The probability of picking either of these colors is simply the sum of their probabilities.

P

green or yellow

=

P

green

+

P

yellow

=

3

11

+

2

11

=

5

11