Let mbe a positive integer such that ϕ(m)=480. Find a positive integer s such that s=234×2(modm), where god(23,m)=1. [7 marks] b. Let p and q are odd primes. By using the contradiction method. prove that pq is not be a perfect number. [Hint σ(n)=n+1 if and only if n is a prime number, where σ is a muliplicative function]