AMC 8 2026 Problem 7

AMC8 2026 年第 7 题

方程与不等式★★☆☆☆

Mika would like to estimate how far she can ride a new model of electric bike on a fully charged battery. She completed two trips totaling 40 miles. The first trip used 1/2 of the total battery power, while the second trip used 3/10 of the total battery power. How many miles can this electric bike go on a fully charged battery?

Mika 想估算她新买的电动自行车充满电后最多能骑行多远。她完成了两次行程，总共骑行了 40 英里。第一次行程消耗了总电量的 1/2，第二次行程消耗了总电量的 3/10。这辆电动自行车充满电后最多能骑行多少英里？

A.45
B.48
C.50
D.52
E.55

正确答案 · Correct Answer

解析 · Solution

解法1

合并分数：

\displaystyle \frac{1}{2} + \frac{3}{10} = \frac{4}{5}

。40 英里用了

\displaystyle \frac{4}{5}

的电量，满电续航

\displaystyle = 40 \div \frac{4}{5} = 40 \times \frac{5}{4} = 50

英里。

Solution 1

Combine the fractions:

\displaystyle \frac{1}{2} + \frac{3}{10} = \frac{4}{5}

of the battery was used for 40 miles. So the full battery range is

\displaystyle 40 \div \frac{4}{5} = 40 \times \frac{5}{4} = 50

miles.

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