快考了，请教prep2 PS 11， 37，38。。。麻烦大家帮忙看一下，多谢

11.   1971-!-item-!-187;#058&002527

Which of the following lists the number of points at which a circle can intersect a triangle?

(A) 2 and 6 only

(B) 2, 4, and 6 only

(C) 1, 2, 3, and 6 only

(D) 1, 2, 3, 4, and 6 only

(E) 1, 2, 3, 4, 5, and 6 (E)

完全没思路

The function f is defined for all positive integers n by the following rule:  f(n) is the number of positive integers each of which is less than n and has no positive factor in common with n other than 1.  If p is any prime number then f(p) =

(A) p - 1

(B) p - 2

(C) 

(D) 

(E) 2 （A）

38.   5275-!-item-!-187;#058&004179

A certain business produced x rakes each month from November through February and shipped 0.5x rakes at the beginning of each month from March through October.  The business paid no storage costs for the rakes from November through February, but it paid storage costs of $0.10 per rake each month from March through October for the rakes that had not been shipped.  In terms of x, what was the total storage cost, in dollars, that the business paid for the rakes for the 12 months from November through October?

(A) 0.40x

(B) 1.20x

(C) 1.40x

(D) 1.60x

(E) 3.20x （C）

第一题划一下图， 很简单的！不行就背答案

第二题 若p is any prime number ， 则f『n』=1 ...p-1, 一共p－1个

第三题画一个表就好了

本人数学极烂

所以弱弱的问一下楼上

第二题中，F(N)的定义好像是正整数的个数，这些正整数必须小于N,并且与N的共因子只有1. 那应该指是小于N的质数的个数吧

如果这样 ,假如P=7 则 F(7)=3 因为比7小的质数只有1、3、5

那F(P)并不是P-1啊，这个时候P-1=6

除非我没看懂题目

请指教