Posted by kejuan on .
Lenny,mark,andliza are going to jog along 3 different trails in the park. To complete one circuit , lenny takes 6 min., Mark takes 12 min., and liza takes 9 min. if they start at the same place and the same time, how long will it be before they are together again at the starting point?

MATH 
bobpursley,
Wouldn't have to be a common factor? something 6,12, and 9 all go into?

MATH 
Mathilde,
Yes, they do. =)

MATH 
drwls,
Look for the least common multiple of 3, 9 and 12. It will have to be the product of at least two 3's and two 2's.