Series is as follows:
(-36 x 1), ( - 36 x 2), (-36 x 3),……
So, 420 – 36 x 6 = 204
The next no. is previous no × 0.3
So 48.6 × 0.3 = 14.58
Series is ( +2 ÷ 2)
(33.75 + 2) ÷ 2 = 17.875
(+2)2, (+4)2, (+6)2, ……..
= 300 + 36 = 336
×1 + 12, ×2 + 22, ×3 + 32, ×4+42
=51 × 4 + 42 = 220