If n is multiple of 5 and n=p2q where p and q are prime numbers which of the following must be a multiple of 25.
1. p^2
2. q^2
3. p*q
4. p^2*q^2
5. p^3*q
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Prime numbers and division
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n = 5 x _
n = p^2 * q = p*p*q
5x_=p*p*q
that means either p = 5 x _
or, q = 5 x _
So, to be sure of multiple of 25.. we need square of both
[spoiler]{D}[/spoiler] p^2*q^2 satisfies
n = p^2 * q = p*p*q
5x_=p*p*q
that means either p = 5 x _
or, q = 5 x _
So, to be sure of multiple of 25.. we need square of both
[spoiler]{D}[/spoiler] p^2*q^2 satisfies
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