N is the product of all the prime numbers less than 100.
Determine the last three digits of N.
*** For an extra challenge, solve this puzzle without the aid of a computer program.
Child of 5: Daddy, I must solve this problem without the aid of a computer program!
Father: A002110 in Sloane contains a list. It's the entry corresponding to the largest prime less than 100.
Child of 5(Much later): Daddy, which number is the largest prime less than 100?
Father: Never mind, try A034386 in Sloane, which has a list of the primorials n# = product of primes <= n. It's the one with "100'next to it.
Child of 5(Reading): So the number is 100 2305567963945518424753102147331756070 and the last 3 digits are 070.
Father: And you did it all without a computer program! My son, you are the new Newton.

Posted by broll
on 20111019 12:02:16 