Allie has a pet snake and feeds every 5th day and a pet lizard she feeds every other day. If she feeds them both today, when is the next day they will BOTH eat?

Question

I NEED HELP IM CONFUSED!

Answer 1

S: F1234F1234F

L: F1F1F1F1F1F

She feeds them both in another 10 days. If today is May 5, the next 5th day is 5+10 = May 15, ten days from today. Unless the snake gets hungry and eats the lizard earlier. If it's a growing snake that could be a problem. Today is the 0th day, (like Ground Zero). five more days is the 5th day. ten more days will be the 10th day, when both get fed. 10 is divisible by 5 and 2.

10 is the least common multiply. LCM. 5 is prime, 2 is prime. 5x2 =10.

every day is: FFFFFF ...

every other day =

every 2nd day: F1F1F1 ...

every3rd day: F12F12F...

every 4th day F123F12...

every 5th day: F1234F...

You're looking for the least common multiple of 5 and 2. IF the problem had been snake eats every 10th day and lizard every 2nd day, then the least common multiple would have been 10, not 10x2=20. break 10 down into prime factors, 5 and 2. Then 10 is divisible by 10 and by 2, the 10th day would be the next time both get fed. The same as in this problem with 5th and 2nd, because the least common multiple is the same.

It's almost a trick question designed to trick you into thinking today is day one, and day 5 is the next time the snake gets fed, as if F234F is the sequence, and the snake gets fed in another 4 days. IF today is considered Day One, then the next snake feeding day is Day 6. 6-1 = 5. So then the "6th day" is the "5th day" from today.