The odd number series are given as 3,5,7,9... The even series is increasing by 4,6,8.... So 2,2+4=6,6+6=12,12+8=20... So next number will be 20

1*2=2 2*3=6 3*4=12 4*5=20

Answer is 72 12*6=72

The odd number series are given as 3,5,7,9... The even series is increasing by multiplication So 2,*6=12 and then 12*6=72 So next number will be 72

The next number in this series : 3 , 2 , 5 , 6 , 7 , 12 , 9 is 20 because

this series contain two series... first series is -> 3,5,7,9....(for next term +2), second series is ->2,6,12.....so next term is 20 because 2+4=6; 6+6=12; 12+8=20(Ans).

Increase every third digit by odd number ex 357.. Starting from 3 3+3 =6 2+5 =7 5+7 =12 6+3 =9 7+5 =12 12+7 =19

On behalf of Sture Sjöstedt