AMC8 1993

AMC8 1993 · Q12

AMC8 1993 · Q12. It mainly tests Arithmetic misc.

See the picture:

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(A) 9 9

(B) 10 10

(D) 16 16

(E) 19 19

Answer

Correct choice: (E)

正确答案：（E）

Solution

Answer (E): The six permutations of $+$, $-$ and $\times$ yield these results: $5 \times 4 + 6 - 3 = 20 + 6 - 3 = 23$ $5 \times 4 - 6 + 3 = 20 - 6 + 3 = 17$ $5 + 4 \times 6 - 3 = 5 + 24 - 3 = 26$ $5 - 4 \times 6 + 3 = 5 - 24 + 3 = -16$ $5 + 4 - 6 \times 3 = 5 + 4 - 18 = -9$ $5 - 4 + 6 \times 3 = 5 - 4 + 18 = 19.$ The only result listed is 19.

答案（E）：$+$、$-$ 和 $\times$ 的六种排列会得到以下结果： $5 \times 4 + 6 - 3 = 20 + 6 - 3 = 23$ $5 \times 4 - 6 + 3 = 20 - 6 + 3 = 17$ $5 + 4 \times 6 - 3 = 5 + 24 - 3 = 26$ $5 - 4 \times 6 + 3 = 5 - 24 + 3 = -16$ $5 + 4 - 6 \times 3 = 5 + 4 - 18 = -9$ $5 - 4 + 6 \times 3 = 5 - 4 + 18 = 19.$ 所列出的结果中只有 19。

Topics

AR.015 Arithmetic misc