If the cost of 12 dozen pens is Rs. 720, then the cost of 25 pens is

Correct option is C

If the cost of 12 dozen pens is 720 /-
Or, the cost of 144 pens is 720 /-
Or, the cost of 1 pen = 720/144
So, the cost of 1 pen = 5/-
Hence, the cost of 25 pens = 25 x 5
= 125/-