Question

Jack plays on a basketball team after school every third day of the month. He babysits his younger brother after school every seventh day of the month. How many times during a 30 day mark if any will jack have a conflict between basketball and babysitting? Explain

Answer 1

1 conflict a month.

Explanation:

To calculate this you just have to calculate the smallest common multiple by multiplying both numbers:

7x3=21

The 21st day of the month he would have to babysit and play basketball after school, so he would have a conflict between the two of them.

Answer 2

Jack will have exactly 1 conflict per month. An easy way to do this is to visualize what he has to do each month.

Basketball:
3, 6, 9, 12, 15, 18, 21, 24, 27, 30
Babysits:
7, 14, 21, 28

Looking above, you can see that only one number is the same, which means there is only one conflict in a 30 day period.