sanaa.rizwan wrote:If n=4p where p is a prime number greater than 2, how many different positive even divisors does n have including n
A.2
B.3
C.4
D.6
E.8
general approach here is
for any no. N = 2^x * 3^y * 5^z ...so on, where x, y and z are their power.
then total no. of factors of N will be (x + 1) * ( y + 1) * (z + 1) ... A
then total no. of odd factors will be ( y + 1) * (z + 1) ... B
then total no. of even factors will be A - B
for example
n = 6 = 2 * 3
total no. of factors = (1 + 1) * (1 + 1) = 4
total no. of odd factors = 2
total no. of even factors = 4-2 = 2
This approach is good when you need to find the even or odd factor of larger no.
I'm no expert, just trying to work on my skills. If I've made any mistakes please bear with me.
