When reading this question, how did you know/assume that "living expenses" are the same as total expenses? What if he had another category of expenses such as spending his earnings on paying for his children's education...would that still count as "living expenses"?
Hi Christina, we don't need to make that assumption here. We know Pat saved $600. This is 1/3 of "the remainder." Hence, "the remainder" is $600*3 = $1800. This $1800 is equal to Pat's earnings after he spent half of it on living expenses. His total earnings, then, were $3600. So he started with $3600, spent $1800 on living expenses, and then saved $600 more. That accounts for $2400. He made $3600, though, so he has $1200 left after taking out his living expenses and savings. He can do whatever he wants with that leftover $1200, as we aren't told what he does with it. He could blow it at the slot machines or pay for his children's education. We're not concerned with the leftover, as we're only told how much he spent on living expenses, and how much he saved. So we don't have to assume that the living expenses are the same as total expenses.
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