A rectangular floor 18 feet by 10 feet is to be completely covered with carpeting that costs x dollars per square yarD.In terms of x, how many dollars will the carpeting cost? (1 yard = 3 feet) E.540x
A.20x B.28x C.60x D.180x
【参考答案】
A 解析：一长为18英尺，宽为10英尺的长方形地板要全部铺上每平方码x美元的地毯。以x为单位，地毯总共需花多少钱?(1码=3英尺) 解：本题的正确答案为(A)。解答该题时，考生一定要注意前后单位的变化，一时疏忽很易选(D)。考虑单位变化，18/3 × 10/3 ×x=20x。