As many apples as Xiao just bought, but I bought 2kg more pears than Xiao Gang, which cost 56.4-44.4= 12 yuan.

So every kilogram of pears (56.4-44.4)÷2=6 yuan.

Xiao Qiang bought 3 kilograms of apples and 1 kg of pears, and * * paid 44.4 yuan, so 3 kilograms of apples cost 44.4-6=38.4 yuan, so (44.4-6)÷3= 12.8 yuan per kilogram of apples.