Question

Find the next two numbers in the following sequence. List the very next missingnumber in Blank 1, and then list the second missing number in Blank 2.

Answer 1

In the sequence 1,5,9,13,.... the difference between two consecutive terms is,

$13-9=4$

This means enext term increases by 4. So term next to 13 is

$13+4=17$

The term next to 17 is,

$17+4=21$

So the sequence is,

$1,5,9,13,17,21$

Answer is

Blank 1: 17

Blank 2: 21