2013 AMC 10B Problem 1

Attempt Problem 1 of the 2013 AMC 10B below, then check your answer against the professionally curated solution from LIVE by Po-Shen Loh. You can also try the full timed exam, view all 2013 AMC 10B solutions, or check the answer key.

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1.

What is the value of the following expression? 2+4+61+3+51+3+52+4+6\frac{2+4+6}{1+3+5} - \frac{1+3+5}{2+4+6}

1 -1

536 \dfrac{5}{36}

712 \dfrac{7}{12}

4920 \dfrac{49}{20}

433 \dfrac{43}{3}

Answer: C
Concepts:fraction
Difficulty rating: 560
Small Hint:

Compute the even and odd sums separately

Big Hint:

Convert both fractions to a common denominator after simplifying

Solution:

2+4+61+3+51+3+52+4+6 =129912=4334=712 \begin{aligned} &\frac{2+4+6}{1+3+5} - \frac{1+3+5}{2+4+6} \\ \ &= \dfrac {12}9 - \dfrac 9{12} \\ &= \dfrac 43 - \dfrac 34 \\ &= \dfrac 7{12} \end{aligned}

Thus, the correct answer is C.

Full Exam

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