AMC8 2002

AMC8 2002 · Q2

AMC8 2002 · Q2. It mainly tests Money / coins, Parity (odd/even).

How many different combinations of \$5 bills and \$2 bills can be used to make a total of \$17? Order does not matter in this problem.

用5美元钞票和2美元钞票凑成总计17美元，有多少种不同的组合？本题中顺序无关。

(A) 2 2

(B) 3 3

(D) 5 5

(E) 6 6

Answer

Correct choice: (A)

正确答案：（A）

Solution

(A) Since the total \$17 is odd, there must be an odd number of \$5 bills. One \$5 bill plus six \$2 bills is a solution, as is three \$5 bills plus one \$2 bill. Five \$5 bills exceeds \$17, so these are the only two combinations that work.

（A）因为总额 \$17 是奇数，所以 \$5 钞票的张数必须是奇数。用 1 张 \$5 加 6 张 \$2 是一种解，3 张 \$5 加 1 张 \$2 也是一种解。5 张 \$5 已经超过 \$17，所以只有这两种组合可行。

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