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 5P1 - P2?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 7.8
P2 is the average of all prime numbers below 12.
prime numbers below 12→2,3,5,7,11
Average = P₁ = (2 + 3 + 5 + 7 + 11)/5
= 28/5
= 5.6
P2 is the average of all prime numbers between 12 and 30.
prime numbers between 12 and 30 → 13, 17, 19, 23, 29
Average = P₂ = (13 - 17 - 19 - 23 - 29)/5
= 101/5
= 20.2
Value of 5P1- P2= 5 × 5.6 - 20.2
= 28 - 20.2
= 7.8