Answer:
0.7 m between the balance point and Tiny
Step-by-step explanation:
It's intuitive to say she sould be on the side the smaller mass is placed. How far from the balance point?
Let's call x that distance. and assume that the contraption is "oriented" so that being on the side with tiny (and teeny) gives you a positive distance from the balance point, and negative on the other side.
At equilibrium, the sum of all momentums (momenta?) will be zero:
In layman's term, she has to be halfway between the balance point and Tiny.