Previous Year NEET Question- Permutation Combination

1. Answer:

(i) The probability of drawing a white ball is $\frac{3}{12} = \frac{1}{4}$.

(ii) The probability of drawing a red ball is $\frac{4}{12} = \frac{1}{3}$.

(iii) The probability of drawing a blue ball is $\frac{5}{12} = \frac{5}{12}$.

Explanation:

The total number of balls in the bag is 3 + 4 + 5 = 12.

The probability of drawing a ball of a particular color is the number of balls of that color divided by the total number of balls.

2. Answer:

There are 5 letters and 4 letter boxes. So, the number of ways in which the letters can be posted in the letter boxes is 5P4 = 5!/(5 - 4)! = 5!/1! = 5! = 120.

Explanation:

The number of ways of arranging 5 letters in 4 letter boxes is 5P4.