Please explain on how to do each of these! *Let (x) be defined for all positive integer values of xas the product of all even factors of 4x. For example, (3)=12x6x4x2=576. What is the value of (5)? Someone says that it is f(5)= 20x10x2x4=1600 I DO NOT GET HOW THEY ARRIVED THAT ANSWER!

Question

Please explain on how to do each of these! *Let (x) be defined for all positive integer values of xas the product of all even factors of 4x. For example, (3)=12x6x4x2=576. What is the value of (5)? Someone says that it is f(5)= 20x10x2x4=1600 I DO NOT GET HOW THEY ARRIVED THAT ANSWER! 
* 2.3 ^5 log(is raised at the same level as 5 meaning not above 5) base 2.3 ^1 The answer is 1 but I do not get how? 
*If p and q are two different prime numbers greater than 2, and n=pq, how many positive factors, including 1 and n, does n have? Do not get how the answer is 4.

saiko · Answer

1>
even factors of 4*5 =20
so the factors are 1, 2 ,4 ,5 ,10 ,20
among them 2,4,10,20 are even.

3>

here 4 is the minimum no of +ve factors.
n will have the factors,
=1*n
=p*q
including 1 and n, n have minimum 4 factors.
it could be more.

***for Q2 I have not understood.