48
http://wiki.answers.com/Q/What_is_the_Lowest_commo...

The lowest common multiple of 5, 7, and 12 is equal to 420.
http://www.chacha.com/question/whatisthelowest...

24*13 = 312. you skip 12, because that's in 24. 26 = 13*2 and 2 is in 24. so 24 * 13 contains all of the prime numbers needed, and is the answer.
http://answers.yahoo.com/question/index?qid=200911...

Just list the multiples of each number until something appears on all three lists. Jockey back and forth until you get it. Multiples of 20 are 20, 40, 60, 80, 100, 120, etc. Multiples
http://answers.yahoo.com/question/index?qid=201111...
