x( 1+25%)= 1560

x = 1560/ 1.25 = 1248

The profit of Book A is1560-1248 = 312 yuan.

The cost of setting up a B book is Y yuan.

y( 1- 10%)= 1350

y= 1350/0.9= 1500

The loss of Book B is1500-1350 =150 yuan.

3 12- 150= 162

The bookstore made a profit this day 162 yuan.