Question 12
Find the missing number.
a) $21,27,33,39,(\quad),51,(\quad),\ldots$
b) $0,3,9,18,30,(\quad),63,\ldots$
c) $1,4,9,(\quad),25,(\quad),\ldots$
d) $2,6,12,(\quad),(\quad),\ldots$
e) $11,88,16,80,21,72,(\quad),(\quad),\ldots$
a) $21,27,33,39,(\quad),51,(\quad),\ldots$
b) $0,3,9,18,30,(\quad),63,\ldots$
c) $1,4,9,(\quad),25,(\quad),\ldots$
d) $2,6,12,(\quad),(\quad),\ldots$
e) $11,88,16,80,21,72,(\quad),(\quad),\ldots$