1, 2, 6, 15, 31, 56, and 91 are all numbers.
A. 31
B. 91
C. 56
D. 15
Answer:B
1, 2, 6, 15, 31, 56, and 91 are all numbers.
A. 31 B. 91 C. 56 D. 15
Explanation: 1, 1 + 12 = 2, 2 + 22 = 6, 6 + 32 = 15, 15 + 42 = 31, 31 + 52 = 56, 56 + 62 = 92,The series' final number must be 92, not 91.