Find the average of all the numbers between 6 and 34 which are divisible by 5. (a) 18         (b) 20       (c) 24        (d) 30

Find the average of all the numbers between 3 and 42 which are divisible by 7

Find the average of all prime numbers between 30 and 50.

Find the average of all prime numbers between 30 and 50.

Find the number of all neutral numbers between 20 and 80, which are divisible by 3.

Six numbers are arranged in decreasing order. The average of the first five numbers is 30 and the average of the last five numbers is 25. The difference of the first and the last numbers is (a) 20 (b) 25quad (c) 5 (d) 30