Answer: 5 friends
Note: if Mariah pays for her own meal, then it would drop to 4 friends.
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Explanation:
Add up the amount she earns:
30.25+25.75+11 = 67
Now add up the amounts that she's either in debt or that she spends money on. Ignore the dinner portion for now.
40+2 = 42
She earns $67 total and has to spend $42, without including the dinner portion just yet. That means Mariah has 67-42 = 25 dollars left over.
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Let x be the number of $5 meals she can buy
So she can spend a total of 5x dollars here. Set this equal to 25 (the amount left over) and solve for x.
5x = 25
x = 25/5
x = 5
She can buy dinner for 5 friends. Or if Mariah is paying for herself as well, then she can buy dinner for 4 friends. It's not clear which scenario your teacher is after, but I'll assume the first scenario.
