Question

What comes next: 2, 3, 10, 15, 26, 35, ?

• A. 50
• B. 57
• C. 47
• D. 49

Answer 1

Answer:

A. 50

Look at the differences between consecutive terms:

• (3 - 2 = 1)

• (10 - 3 = 7)

• (15 - 10 = 5)

• (26 - 15 = 11)

• (35 - 26 = 9)

So the differences are:

1, 7, 5, 11, 9, ...

These form two interleaved sequences:

• $(1, 5, 9, \ldots) (increase by 4)$

• $(7, 11, 15, \ldots) (increase by 4)$

The next difference should be 15.

Therefore,

35 + 15 = 50

Answer: $(\boxed{50})$