Let the discount price of surplus clothes be X yuan, and the equation can be listed:

100 * 60% * 200 * 50%+ 100 *( 1-60%)*(x-200)= 100 * 200 *(50%- 18%)

6000+40x-8000=6400

x=2 10

2 10/300=0.7

So the rest of the clothes are sold at a 30% discount.