Question

Susie says that it she has a quick way to determine the least common multiple of two numbers; you just multiply the numbers. Susie checked it with 3 and 5 and with 4 and 7 and method worked both times. Is Susie’s method a valid way to determine the least common multiple of two counting numbers? Explain.

Answer 1

No, it is not a valid way

Explanation:

Required

Is Susie's method valid?

Susie's method worked because 4 & 7 and 3 & 5 do not have a common factor.

In other words, Susie's method will not work when the two numbers have a common factor.

Take for instance, the LCM of 2 and 4.

Using Susie's method, the LCM will be 8 (i.e. 2 * 4) whereas the LCM is 4.