Question : P₁ is the average of all prime numbers below 12 and P2 is the average of all prime numbers between 12 and 30. What is the value of 5P_{1 –} P₂?

Option 1: 7.8

Option 2: 8.6

Option 3: 9.8

Option 4: 7.5

Question : The average of prime numbers between 1 and 20 is:

Option 1: $9$

Option 2: $9\frac{5}{8}$

Option 3: $10\frac{1}{8}$

Option 4: $8$

Question : What will be the average of all the prime numbers between 9 and 22?

Option 1: 14

Option 2: 15

Option 3: 10

Option 4: 12

Question : The average of ten numbers is 24. If each number is divided by 2, then what will be the new average?

Option 1: 12

Option 2: 6

Option 3: 20

Option 4: 5

Question : The average of 21 numbers is 60. If each number is increased by 20, then find the number by which the average is increased.

Option 1: 12

Option 2: 18

Option 3: 15

Option 4: 20