Let E be the elliptic curve y^2 = x^3 + 6x modulo 11 and consider the point P = (2, 3) on it.

How do I compute 3P

I have been able to figure out what 2P is, 2P = (5,10) mod 11

However I am unsure if even knowing 2P is helpful, or do I just compute 3P from knowing the original P?