Question

4, 9, 19, 39, 79, ?

• A. 169
• B. 159
• C. 119
• D. 139

Answer 1

Answer:

B. 159

4 + 5 = 9 9 + 5×2 = 19 19 + 10×2 = 39 39 + 20×2 = 79 79 + 40×2 = 159