Torque, Equilibrium, and Center of Mass

[Lyphta]

Homework Statement

While standing on a long board resting on a scaffold, a 70 kg painter paints the side of a house. If the mass of the board is 15 kg, how close to end can the painter stand without tipping the board over?
http://img146.imageshack.us/my.php?image=physicssl9.jpg

Homework Equations

$$\tau$$painter = $$\tau$$board

The Attempt at a Solution

$$\tau$$painter = $$\tau$$board
(rpainter) (70kg) = (1.5 m) (15kg)
70r = 22.5
r=.32 ft.

the answer was 1.2 m from left end of board.

 

[kuruman]

Sorry, without a picture showing how and where the board is supported, we cannot figure out the correct solution. We are certain, however, that $\tau$ is an incorrect answer.