Complete the series: 6, 9, 13, 16, 20, 23, …….. A) 26, 30 B) 26, 31 C) 27, 30 D) 27, 31 Solution First add 3 the 4 in whole series: 6+3=9 , 9+4=13 13+3=16 , 16+4=20 20+3=23 , 23+4=27 27+3=30