John's dad picks him up from school every third day. Aaron's mum picks him up from school every other day. If they meet on the first day, how many times will they meet over three weeks?
John's dad picks him up on day: 1 4 7 10 13 16 19
Aaron's mum picks him up on day: 1 3 5 7 9 11 13 15 17 19.
So the days they meet are: day 1, 7, 13 and 19.
However, the answer supposed to be 3 not 4. Does anyone know why?
They did not mention that the first day does not count.
My dd came up with an explanation that since they go to school 5 out of 7 days so in three weeks that would be 3x5=15 days. And in the 15 days there are then only 3 times they meet.
However, we don't know which days the weekend falls on so not tusre what is the right way to approach it.
Any maths experts please enlighten us with your wisdom.
