In the following series find the term in place of question mark? 15, 30, 60, 105, 165, ?

Correct option is D

The differences are: 30 – 15 = 15 60 – 30 = 30 105 – 60 = 45 165 – 105 = 60 Next diff = 75 → 165 + 75 = 240 Explanation of options: (a) ✘ 210 is short by 30 (b) ✘ 220 is short by 20 (c) ✘ 230 is short by 10 (d) ✔ Correct continuation with +75 pattern