Question

1, 5, ?, 66, 280…

• A. 20
• B. 18
• C. 22
• D. 26

Answer 1

Answer:

B. 18

1, 5, ?, 66, 280 

1 x (1+4) = 5

2 x (5+4) = 2 x 9 = 18

3 x (18+4) = 3 x 22 = 66

4 x (66+4) = 4 x 70 = 280