Student: Look at this series: 72, 76, 73, 77, 74, __, 75, ... What number should fill the blank?
Options:
(A) 70
(B) 71
(C) 75
(D) 78
(E) 74.
Another student: Let's say, hmmm...
There will be 2 series
1st: 72 73 74 75 76 (Increasing by 1)
2nd: 76 77 78 79 (Increasing by 1)
Final: 72 76 73 77 74 78 75 Final answer: (D).