Suppose: the quantity of book A is X, the quantity of book B is Y, and the price of book A after 10% discount is T.

Then:

x & gt 100。 100

y=0.6x

X×t=y× 1.5×2 (bringing y=0.6x into the formula)

Get: x× t = 0.6x× 1.5x2.

T= 1.8 yuan

Because t= 1.8 yuan is the price after 10% discount, the original copy of Book A is 1.8 yuan /0.9=2.0 yuan.