P₁ is the average of all prime numbers below 12. P₂ is the average of all prime numbers between 12 and 30. What is the value of 5P₁ – P₂?

7.8

                  2,3,5,7,11                 13,17,19,23,29

Average          \(\frac{28}{5}\)                          \(\frac{101}{5}\)

Now,               5P₁                                    P₂

                    \(\frac{5 × 28}{5}\)                          \(\frac{101}{5}\)

Hence,

5P₁ – P₂= 28 - 20.2 =7.8