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.
(In reply to two-thirds of a solution.
By the same logic you used for the last digit, can we not determine the third-to-last digit by considering the 'tens' values for the list of primes- some are in the 20s and some in the 50s, giving 2x5 = 10 again for this missing digit.
Making the last three digits 070.
Posted by Matt
on 2011-10-19 12:14:59