Mr. P's teenaged girlfriend Miss Q is a student of mathematics. Miss Q brought a well framed crochet with a polynomial in X ( having integer coefficients ) stitched on it as the birthday present on his birthday sometime this year. The polynomial is so constructed that one of its roots is equal to Mr. P's age ( in years) on his birthday (this year).

Someone present at the birthday party tried to find its root, not being aware that the root stood for the age of the host. He substituted X=8, which gave him 64. He tried a different number slightly greater than 8 but less than 16, which gave him 70.

If Mr. P is older than his 16- year old girlfriend, how old was he on his birthday this year?