Camels and dromedaries

Camels and dromedaries

If we have 48 legs and 20 humps in our herd of camels and dromedaries,

How many dromedaries are in the group?


If we divide the number of legs by 4 we get the total number of animals that are 12.
Now we distribute a hump for each animal and we see that there are 8 left over that correspond to the camels that have 2 humps each. Therefore we have 12 - 8 = 4 dromedaries.