The x is smaller!
The positive number is the product of four different positive prime numbers. If the sum of these four prime numbers is a prime number greater than 20, what is the least positive value of ?
The answer is 390.
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1 solution
Let's begin listing the four prime numbers, checking if the sums are prime and begin with smaller numbers :
2, 3, 5, 7 : Sum = 17, too small
2, 3, 5,11: Sum = 21, not prime
2, 3, 7,11:Sum = 23, prime
2, 3, 5,13:Sum = 23, prime
2(3)(7)(11) = 462
2(3)(7)(11) = 390
390 is the smallest, so it is the least positive integer.