Direct and Indirect Proof

Q.

Question 85

Solve the following:

The sum of three consecutive odd natural numbers is 69. Find the prime number out of these numbers.

Q. Proving "A prime number greater than 2 is odd." is an example of which type of proof?

1. Direct proof
2. Indirect proof

Q.

Question 1 (i)
Classify $2-\sqrt{5}$ as rational or irrational.

Q. Proving $\sqrt{2}$ is an irrational number is an example of a/an.

1. direct proof
2. indirect proof
3. postulate

Q. Proving $\sqrt{2}$ is an irrational number is an example of which type of proof?

1. Direct
2. Indirect