You’re not trying to maximize Bob’s earnings. Instead, you’re trying to maximize the other employees’ earnings, given that Bob earns more than all other employees. This is equivalent to asking “what is the maximum earning we can assign to one employee, say Alice, while still ensuring that Bob earns more than Alice, and all other employees earn at most what Alice earns”? Well, if we suppose that Bob earns $x$, then the most Alice could earn is $x-1$. In order to ensure that Alice (and therefore Bob, as wel) earns the most she could possibly earn under the given assumptions, we then require that each other employee only earn $75$. Does this make sense? Can you use this information to formulate an equation in terms of Bob’s earnings, $x$?