Torque--easy problem--plank

Jeeves and Wooster are playing around on a long 10 kg plank. The plank has two supports, one 2 m from the left end, the other is 4 m from the right end.
Jeeves (50 kg) stands on the left end of the 9 m long plank. Wooster (75 kg) walks towards the other side of the plank. Can Wooster walk all the way to the right end of the plank without it tipping over? If not, how far can he walk before it just starts to tip?