Answer-If 236 = 33, 487 = 57, 6391 = 57, then 851 = ?

The logic followed here is as follows The sum of all the digits of the number, and then the sum is multiplied by 3. For 236 33 2 3 6 113 33 For 487 57 4 8 7 19 3 57 For 6391 57 6 3 9 119 3 57 Similarly, for 851 8 5 1 14 3 42