Which two numbers should come next in the sequence? 11, 24, 21, 34,

Answer 1

11, 24, 21, 34 is a sequence of the form x, y, x+10, y+10, x+20, y+20, x+30, y+30, ...

11, 24, 21, 34, 31, 44, 41, 54, ...

the odd terms are an arithmetic sequence of the form an= a1 +10(n-1)

11, 21, 31, 41, 51, ...

the even terms are an arithmetic sequence of the form an =a1 +10(n-1)

24, 34, 44, 54, ....

then put the two sequences together, a1 from the 1st sequence, a2 from the 2nd sequence, and alternate them

the 5th term is 31

the 6th term is 44