If 40, 50, ?, 104. What is the solution for ?.

Question

What number does the ? mark equal

Answer 1

40, 50, 76, 104.

If we look at these numbers as angles and take them in pairs considering quadrants, the smaller of the first pair is the complement of the larger: 40=90-50. These angles complete the first quadrant.

In the second pair we consider the second quadrant: 90-180. The smaller of this pair is the supplement of the larger: 76=180-104. These angles complete the second quadrant.