Thanks for your answer, but the right answer is A. p-1
So I don't know how to do it right

Please help

1. The function f is defined for all positive integer n by the following rule: f(n) is the number of positive integers each of which is less than n and has no common factor with n other than 1. If p is any prime number than f(p)= A. p-1 B. p-2 C. (p+1)/2 D. (p-1)/2 E. 2 2. A certain car averages 25 ...

Im still confused abt this question

if n and k are integers whose product is 400, which of the following statements must be true? A. n+k>0 B. n#k C. either n or k is multiple of 10 D. if n is even, then k is odd E. if n is odd, then k is even what is the different between D and E? They both indicate the same thing that: one of each is...

Please help explain

1. Are x and y both positive?
1. 2x-2y=1
2.x/y>1

2. IF p is a prime number greater than 2, what is value of p?
1. there are total 100 prime number between 1 and p+1
2. there are total p prime number between 1 and 3912

Thanks

PS question

If two sides of a triangle have lengths 2 and 5, which of the following could be the perimeter of the triangle? I. 9 II. 15 III. 19 A. None B. I only C. II only D. II and III only E. I, II, and III I think the answer is B, because the triangle with 2 sides of 2 and 5 can have the third side of 2, th...

but it is can also be D, because we just need either n or k is even, why not D

Another question regarding counting

How many intergers between 324,700 and 458,600 have tens digit 1 and units digit 3?
A. 10,300
B. 10,030
C. 1,353
D. 1,352
E. 1,339


Is there any general strategy to approach counting question?


Thanks a lot

I do not understand the this question, please help

Please help to explain the question in the attachment. Thanks