Discount mathematics problem

Total purchase price: 2.4*300 yuan,

So the profit is: 2.4*300* 15%= 108 yuan.

12 yuan, 20% discount is 12*0.8=9.6 yuan,

Another 20% discount is: 9.6*0.8=7.68 yuan.

So in the end, the selling price lost money, and each unit lost (8-7.68)=0.32 yuan.

1* * profit: 60% *180 * (12-8)+40 * (9.6-8)-0.32 * (180 * 40%-40).

=432+64- 10.24

=485.76 yuan

The profit of 80% shirts is: 80 * 25% *120 * 80% =1920 yuan.

The remaining 20% profit is: 2040- 1920= 120 yuan.

The profit per piece is: 120/( 120*20%)=5 yuan.

That is, the discounted price is 80+5=85 yuan, and the original price is 80* 1.25= 100 yuan.

So 85/ 100=0.85, which means 15% discount.

Suppose the business cost of B is X yuan, then A is 200-X yuan.

Then after pricing, Party A is 1.3(200-X) and Party B is1.2x.

After another 10% discount, it will be 1.3*0.9*(200-X), and B will be 1.2X*0.9.

The profit per piece is:1.3 * 0.9 * (200-x)+1.2x * 0.9-200.

The planned profit is:1200 * 0.25 * 40% =120 yuan.

The actual profit is 86%* 120= 103.2 yuan.

The first 80% profit is: 1200*80%*.25*40%=96 yuan.

The final 20% profit is 103.2-96=7.2 yuan.

The profit per book is: 7.2/( 1200*20%)=0.03 yuan.

The price is 0.25+0.03=0.28 yuan.

The planned price is: 0.25* 1.4=0.35 yuan.

So 0.28/0.35=0.8.

That's 20% off.