The elves and reindeer are getting ready for a meeting with Santa. So far 14 of them have arrived.
If they have 38 legs between them, how many reindeer are at the meeting and how many elves are at the meeting?

Let and be the number of elves and reindeers, respectively.

We know that:

(so far 14 of them have arrived)

(each reindeer has 4 legs and each elf has two)

If we multiply the first equation by 2 we have , and if we subtract this equation from the second we have which implies .

So, there are 5 reindeers and 9 elves (remember that they have to sum up to 14).

ab will be equal to