If: 2=6, 3=12, 4=20, 5=30, 6=42, 9=??
your answer would be 9=72 they are just multiplying the first number by 3 then 4 then 5 and so on and so on
23=6, 34=12, 45=20, 56=30, 67=42, 78=56, 89=72, 910=90. 90 is your final answer
