问题
单项选择题
A circular rim 28 inches in diameter rotates the same number of inches per second as a circular rim 35 inches in diameter. If the smaller rim makes x revolutions per second, how many revolutions per minute does the larger rim make in terms of x ？（）
A.A
B.B
C.C
D.D
E.E
答案
参考答案：C
解析：
考生在做这类题时一定要倍加小心，题目中给出的每秒转多少圈，而最后问的是每分钟转多少圈，因此考生一定要注意单位的换算。根据题意可得大轮每分钟转这的圈数为48x。