Question 24: Suppose the purchase price of the first batch of stationery is X yuan and the quantity is Y.

xy= 1050

1.2x *(y+ 10)= 1440

solve

x= 15

y=70

So the price of the first batch of stationery is 15 yuan.

15* 1.2= 18 yuan, the second purchase price.

70+ 10=80 The quantity of the second batch is 80.

Let the second batch of sales price be X yuan.

96=x*80- 18*80

80x= 1536

x= 19.2

19.2/24=0.8

So the minimum discount is 20%.