1.60×1.5÷ 5/9
=90×9/5
=162(千米)
答:A、B两城相距162千米.
2.12÷(1+2×10%)
=12÷1.2
=10(元)
10×10%=1(元)
答:买一支钢笔要花10元买一本练习本要花1元.