Question

某场共养鸡和鸭80只,后来鸡卖出五分之一,鸭又卖进12只,这时鸭的只数正好是鸡的3分之2,求鸡和鸭原来各

Answer 1

设鸡为X,鸭为80-x

2[x-0.2x]=3[80-x+12]

2x-0.4x=240-3x+36

1.6x=276-3x

1.6x+3x=276

4.6x=276

x=60

80-60=20

答：鸡为60,鸭为20.

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