Karan bought a little box of midget matches, each one inch in length. He found that he could arrange them all in the form of a triangle whose area was just as many square inches as there were matches.
He then used up six of the matches, and found that with the remainder he could again construct another triangle whose area was just as many square inches as there were matches.
And using another six matches he could again do precisely the same.
How many matches were there in the box originally?