Question

Continue the series: 135, 83, 52, 31, 21. . .

Answer 1

10

Explanation:

Each term is the sum of the two after it:

a_n = a_n+1 + a_n+2

The next term is:

a₄ = a₅ + a₆

31 = 21 + a₆

a₆ = 10