Question

WHAT NUMBER COMES NEXT IN THE SERIES? 21,5,19,7,17,9,

Answer 1

Answer:

15 comes next in the series.

For numbers 21, 19 , 17, we see that they are reduced by 2 each.

while for 5, 7, 9 they are increased by 2 each.

Answer 2

The alternative numbers starting from 21 is being subtracted by 2 and the other set is being added by 2.

So the next number will be 15 , 11