Snake-Eyes Magoo is a man of habit. For instance, his Friday evenings are all alike-into the joint with his week's salary of $180, steady gambling at "2-up" for two hours, then home to his family leaving $45 behind. Snake Eyes's betting pattern is predictable. He always bets in amounts proportional to his cash at hand, and his losses are also predictable-at a rate proportional to his cash at hand. This week Snake-Eyes received a raise in salary, so he played for three hours, but as usual went home with $135. How much was his raise?