Question

Find the missing numbers:

$21,24,27,30,?$

Answer 1

As per series given we have to figure out the 5th term of the series a, a+d, a+2d...
where $a=21$ and$d=3$
Therefore
5th term$=a+4d$
5th term$=21+4\times 3$
$=21+12$
$33$
Answer is $33$