2013 AMC 8 Problem 4

Attempt Problem 4 of the 2013 AMC 8 below, then check your answer against the video solution and professionally curated solution from LIVE by Po-Shen Loh. You can also try the full timed exam, view all 2013 AMC 8 solutions, or check the answer key.

All problems are used with official legal permission of the Mathematical Association of America (MAA).

4.

Eight friends ate at a restaurant and agreed to share the bill equally. Because Judi forgot her money, each of her seven friends paid an extra $2.50\$2.50 to cover her portion of the total bill. What was the total bill?
$120\$120
$128\$128
$140\$140
$144\$144
$160\$160
Answer: C
Concepts:money
Small hint:
The seven friends together paid Judi’s share.
Big hint:
Judi’s share is 77 times the extra amount each friend paid.
Video solution:
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Written solution:
Since Judi’s portion was fully covered by everyone’s contributions, the portion of the bill she was responsible for was equal to 7⋅$2.50=$17.50.7 \cdot \$2.50 = \$17.50.
As everyone paid the same amount, we can conclude that the total bill is 8⋅$17.50=$140.8 \cdot \$17.50 = \$140.
Thus, C is the correct answer.
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