Consider the following premises. Jessica is a cashier or it is overcast. It is windy if and only if Jessica is a cashier. If it is windy, then Mary is not climbing a mountain. Mary is climbing a mountain. Can we infer the following from them? It is not overcast.
 From the fact that if it is windy, then Mary is not climbing a mountain, and that Mary is climbing a mountain we can infer that it is not windy. From the fact that it is windy if and only if Jessica is a cashier, and that it is not windy we can infer that Jessica is not a cashier. Finally, from the fact that Jessica is a cashier or it is overcast, and that Jessica is not a cashier we can infer that it is overcast, which contradicts that It is not overcast. Therefore, the answer is no.