What values are you using when you solve the young equation?
You are basically given information (contact angles and tensions) for two solid-liquid-air systems (water-air-solid and benzene-air-solid, air implied) and asked to use that information to solve for the water-benzene-solid system. So, you'll need to use the contact angles given for the air systems to solve for the missing information in the air systems, and use that missing information to solve for the contact angle in the liquid-liquid-solid system. If that makes sense.
Do you understand the bit about using mutually saturated liquids?