10. The Math department has three different photocopiers, which I call copier A, copier B, and copier C. Copier A is not working 10% of the time. Copier B is not working 7% of the time. Copier C is not working 5% of the time. Assume that the copiers function independently. If it is known that exactly one of the three photocopiers are functioning, what is the proba- bility that it is copier A which is functioning