Question

1,2,5,10,17,......
1) 20
2) 22
3) 24
4) 26

Answer 1

0+1+1=1

1+2+3=5

1+2+5=10

2+5+10=17

5+10+17=32

Answer 2

(4) 26.

The nth term of the series is (n - 1)² + 1.