Find the next number in the series
12, 20, 40, 72, 116, 172 ?
* This question was asked in polaris
240
40 { diff 20 + 12 =>32 add to it}
72 { diff 32 + 12 =>44 add to it}
116 { diff 44 + 12 =>56 add to it}
172 { diff 56 + 12 =>68 add to it}
240
