Question

1. A bag contains 40 marbles, 28 red ones and 12 blue ones. A marble is picked at random

from the bag.

What is the probability of picking:
a) a red marble _____
b) a blue marble _____
c) a yellow marble _____​

Answer 1

a) 0.7

b) 0.3

c) 0

Explanation:

Number of marbles in the bag:

• 28 red marbles
• 12 blue marbles

⇒ total marbles = 28 + 12 = 40

`\sf Probability\:of\:an\:event\:occurring = (Number\:of\:ways\:it\:can\:occur)/(Total\:number\:of\:possible\:outcomes)`

Therefore:

`\implies \sf P(red\:marble)=(28)/(40)=0.7`

`\implies \sf P(blue\:marble)=(12)/(40)=0.3`

`\implies \sf P(yellow\:marble)=(0)/(40)=0`

(As there are no yellow marbles in the bag, the probability of picking a yellow marble is zero)

Answer 2

Required Answer :

Given :-

• A bag contains 40 marbles
• 28 red ones
• 12 blue ones
• A marble is picked at random from bag

To Find :-

• Probability of picking a) a red marble b) a blue marble c) a yellow marble?

Solution :-

As we clearly know that probability is given by;

• Probability = (Possible outcomes)/(Total number of outcomes)

a)

• Probability of a red marble

→ Probability = (No. of red marbles)/(Total marbles)

→ Probability = 28/40

→ Probability = 0.7

b)

• Probability of a blue marble

→ Probability = (No. of blue marbles)/(Total marbles)

→ Probability = 12/40

→ Probability = 0.3

c)

• Probability of a yellow marble

→ Probability = (No. of yellow marbles)/(Total marbles)

→ Probability = 0/40

→ Probability = 0

Hence, solved!