A man sells two horses for Rs, 4000 each, neither losing nor gaining in the deal. If he sold one horse at a gain of 25% the other horse is sold at a loss of?

C.P. of two horses = Rs. 8000
S.P. of one horse = Rs. 4000
Gain = 25%
∴ C.P. of this horse = Rs (100/125) x 4000 = Rs.3200
C.P. of another horse = Rs. (8000 - 3200) = Rs. 4800
S.P. of this horse = Rs. 4000
∴ Loss% = (800/4800) x 100 % = 16²/₃%