The numbers are a, b, c, d, e, f
As they are consecutive even integers they can be expressed as a, a+2, a+4, a+6, a+8.
Average = sum of the integers / Total Number of integers
A = (a + a+2 + a+4 + a+6 + a+8)/ 5
A = (5a + 20)/ 5
A = 5(a + 4)/ 5 = a+4
2nd Part : same as above, as the difference between two consecutive odd integers are also 2.
Thus, answer is option (d) a+4