Question

Dexter mows his law every 12 days and washes his windows every 30 days. He mowed his lawn and washed his windows today.How many days from now will it be until he mows his lawn and washes the windows on the same day

Answer 1

60 days

Explanation:

To find when the two actions will happen together again, we just need to find the least common multiple of 12 and 30.

To do this, first we factor them in prime numbers:

12 = 2 * 2 * 3

30 = 2 * 3 * 5

Now we choose one of them and add the prime factors that the number chosen does not have from the other.

If we choose 30, we should add a number 2, so 2 * 30 = 60

If we choose 12, we should add a number 5, so 12 * 5 = 60

So after 60 days Dexter will mow his lawn and wash the windows on the same day.