A bag has 5 red marbles, 4 green marbles and 3 blue marbles. All marbles are identical in all respects other than colour. A marble is taken out from the bag without looking into it. What is the probability that it is a non-green marble?
1. \(\frac{7}{12}\)
2. \(\frac{5}{12}\)
3. \(\frac{1}{3}\)
4. \(\frac{2}{3}\)
1. \(\frac{7}{12}\)
2. \(\frac{5}{12}\)
3. \(\frac{1}{3}\)
4. \(\frac{2}{3}\)
Correct Answer – Option 4 : \(\frac{2}{3}\)
Given:
The bag has red marbles = 5
The bag has green marbles = 4
The bag has blue marbles = 3
Concept used:
The probability formula is used to compute the probability of an event to occur. To recall, the likelihood of an event happening is called probability.
Formulae required:
Probability P(A) = the number of favourable outcomes/total number outcomes
Calculations:
The total number of marbles = 5 + 4 + 3
⇒ 12
Non- green marble = not green
The non-green marbles in a bag = total marbles – green marbles
⇒ 12 – 4 = 8
Probability of non-green marble = 8/12
⇒ 2/3
∴ The probability that it is a non-green marble is 2/3