Three of the following number triads are alike in some manner and one is different. Select the odd number triad.
(NOTE: The second and third numbers in the given number triads are formed by performing a certain operation on the first number. The same operation is followed in all the number triads except one. Find that odd number triads.)
1
3 ∶ 21 ∶ 147
2
8 ∶ 56 ∶ 3100
3
1 ∶ 7 ∶ 49
4
10 ∶ 70 ∶ 490