What should come in place of the question mark (?) in the following number series.
12 6.5 7.5 12.75 27.5 71.25 ?
(a) 225.75 (b) 216.75 (c) 209.75 (d) 236.75 (e) 249.75
(b) The given number series is based on the following pattern:
12 × 0.5 + 0.5 = 6.5
6.5 × 1 + 1 = 7.5
7.5 × 1.5 + 1.5 = 12.75
12.75 × 2 + 2 = 27.5
27.5 × 2.5 + 2.5 = 71.25
? = 71.25 × 3 + 3
= 213.75 + 3 = 216.75
Hence, 216.75 will replace the question mark.
