12) A die is thrown at random. Find the probability of getting:
(i) 2
(ii) A number less than 3
(iii) A composite number
(iv) A number not less than 4



Answer :

Let's solve the problem step-by-step.

### Understanding the problem

A standard die has 6 faces with the numbers 1, 2, 3, 4, 5, and 6. When a die is thrown, each face has an equal probability of landing face up. Therefore, there is a total of 6 possible outcomes.

### (i) Probability of getting a 2

A die has one face showing the number 2. Therefore, there is only one favorable outcome (i.e., getting a 2) out of the total 6 possible outcomes.

[tex]\[ \text{Probability of getting a 2} = \frac{\text{Number of favorable outcomes}}{\text{Total number of outcomes}} = \frac{1}{6} \][/tex]

The result in decimal form is approximately:
[tex]\[ \text{Probability of getting a 2} ≈ 0.1667 \][/tex]

### (ii) Probability of getting a number less than 3

A number less than 3 on a die can be either 1 or 2. There are 2 favorable outcomes (i.e., getting a 1 or a 2).

[tex]\[ \text{Probability of getting a number less than 3} = \frac{\text{Number of favorable outcomes}}{\text{Total number of outcomes}} = \frac{2}{6} = \frac{1}{3} \][/tex]

The result in decimal form is approximately:
[tex]\[ \text{Probability of getting a number less than 3} ≈ 0.3333 \][/tex]

### (iii) Probability of getting a composite number

Among the numbers on a die (1, 2, 3, 4, 5, 6), the composite numbers are 4 and 6. Composite numbers are numbers that have more than two distinct divisors. Therefore, there are 2 favorable outcomes (i.e., getting a 4 or a 6).

[tex]\[ \text{Probability of getting a composite number} = \frac{\text{Number of favorable outcomes}}{\text{Total number of outcomes}} = \frac{2}{6} = \frac{1}{3} \][/tex]

The result in decimal form is approximately:
[tex]\[ \text{Probability of getting a composite number} ≈ 0.3333 \][/tex]

### (iv) Probability of getting a number not less than 4

A number not less than 4 on a die can be 4, 5, or 6. There are 3 favorable outcomes (i.e., getting a 4, 5, or 6).

[tex]\[ \text{Probability of getting a number not less than 4} = \frac{\text{Number of favorable outcomes}}{\text{Total number of outcomes}} = \frac{3}{6} = \frac{1}{2} \][/tex]

The result in decimal form is:
[tex]\[ \text{Probability of getting a number not less than 4} = 0.5 \][/tex]

### Summary

(i) The probability of getting a 2 is approximately 0.1667. \
(ii) The probability of getting a number less than 3 is approximately 0.3333. \
(iii) The probability of getting a composite number is approximately 0.3333. \
(iv) The probability of getting a number not less than 4 is 0.5.