Question

A box contains 24 pencils. Some of these pencils are green and others are red in colour. If a pencil is taken at random from the box, the probability that it is green is \(\frac{1}{3}\). Find the number of red pencils in the box.
1. 10
2. 8
3. 16
4. 3 

Answer 1

Correct Answer - Option 3 : 16

Given:

Total Pencils = 24

Probability of picking green pencil = \(\frac{1}{3}\)

Formula use:

Probability of picking red pencil = \(X\over24\)

Calculation:

Probability of picking red pencil = \(1-{1\over3}\)

Probability of picking red pencil = \({2\over3}\)

We know,

Probability of picking red pencil = \(X\over24\) = \({2\over3}\)

⇒ \(X= {{2×24}\over3}\)

⇒ \(X=2×8\)

⇒ \(X=16\)

Therefore, the probability of picking red pencil is 16.

Hence, the correct answer is 16.