A$=1,$ B$=16$ and C$=7$

A bullet of mass $(7\mathrm{.}5+$ A$)$ g is fired into a block of wood of mass $(0\mathrm{.}35+($B$/100))$ kg suspended by a $(0\mathrm{.}80+($C$/10))$ m long string. If the block swings up so the strings make an angle of $64\mathrm{.}0$ degrees from vertical, what was the initial speed of the bullet?