A store buys 600 souvenirs, and the purchase price is each 6 yuan. In the first week, 200 souvenirs were sold at the price of 10 yuan, and in the second week, they were sold at the price of 10 yuan.

Solution: from the meaning of the question:

200×( 10﹣6)+( 10﹣x﹣6)(200+50x)+[(4﹣6)(600﹣200﹣(200+50x)]= 1250，

That is 800+(4 ~ x) (200+50x) ~ 2 (200 ~ 50x) =1250,

Finishing: x 2 ~ 2x+ 1 = 0,

Solution: x 1 =x 2 = 1,

∴ 10﹣ 1=9,

A: The sales price for the second week is 9 yuan.