The number of ordered pair (p,q) (p and q are prime,`p!=q` ) such that `p^(2)+7pq+q^(2)` is the square of an integer

The number of ordered pairs (p,q) such that the LCM of p and q is 2520

If p and q are primes such that p=q+2 prove that p^(p)+q^(q) is a multiple of p+q

If p,q and r are prime numbers such that r=q+2 and q=p+2 , then the number of triples of the form (p,q,r) is

If p/q = 5/7 then (p^(2)+q^(2))/(q^(2))=square

r, s, t are prime numbers and p, q are natural numbers such that LCM of p, q is r^(2)" "s^(4)" "t^(2) , then the number of ordered pairs (p,q) is

The number 0.7 in the form (p)/(q) , where p and q are integers and q =! 0 is

If r,s,t are prime numbers and p,q are the positive integers such that LCM of p,q is r^(2)s^(4)t^(2) , then the number of ordered pairs (p,q) is: