AMC 10 Daily Practice Round 2

Complete problem set with solutions and individual problem pages

Problem 1 Easy

Define a※b=\frac{a-b}{a+b} for all real numbers a and b. Find the value of 5※(4※3).

  • A.

    \frac{16}{17}

  • B.

    \frac{17}{18}

  • C.

    \frac{18}{19}

  • D.

    \frac{19}{20}

  • E.

    \frac{21}{22}

Answer:B

43=\frac{4-3}{4+3}=\frac{1}{7},

5\frac{1}{7}=\frac{5-\dfrac{1}{7}}{5+\dfrac{1}{7}}=\frac{17}{18}.

5※(43=\frac{17}{18}.