For any integer n greater than 1, n* denotes the product of all the integers from 1 to n, inclusive....
For any integer n greater than 1, n* denotes the product of all the integers from 1 to n, inclusive. How many prime numbers R are there between 6* + 2 and 6* + 6, inclusive?
Answer/Solution
None
Steps/Work
Given that n* denotes the product of all the integers from 1 to n, inclusive so, 6*+2=6!+2 and 6*+6=6!+6.
Now, notice that we can factor out 2 our of 6!+2 so it cannot be a prime number, we can factor out 3 our of 6!+3 so it cannot be a prime number, we can factor out 4 our of 6!+4 so it cannot be a prime number, ... The same way for all numbers between 6*+2=6!+2 and 6*+6=6!+6, inclusive. Which means that there are no primes R in this range.
Answer: A.
Now, notice that we can factor out 2 our of 6!+2 so it cannot be a prime number, we can factor out 3 our of 6!+3 so it cannot be a prime number, we can factor out 4 our of 6!+4 so it cannot be a prime number, ... The same way for all numbers between 6*+2=6!+2 and 6*+6=6!+6, inclusive. Which means that there are no primes R in this range.
Answer: A.