AMC 8 2024 Problem 10
AMC8 2024 年第 10 题
表达式与运算★☆☆☆☆
In January 1980, the Mauna Loa Observatory recorded carbon dioxide (CO₂) levels of 338 ppm (parts per million).
Over the years, the average CO₂ reading has increased by about 1.515 ppm per year.
What is the expected CO₂ level in January 2030, in ppm? Round your answer to the nearest integer.
1980年1月，莫纳罗亚天文台记录的二氧化碳浓度为338ppm（百万分之一)。近年来，二氧化碳浓度平均每年增加约1.515ppm。请问2030年1月的二氧化碳浓度预计为多少ppm？将答案四舍五入到最接近的整数。
- A.399
- B.414
- C.420
- D.444
- E.459
正确答案 · Correct Answer
B
解析 · Solution
解法1
这是一个时间周期为2030 = 50年，因此我们可以预期ppm增加 ppm。由于我们从338 ppm开始，我们有76+338= 。
2030 - 1980 = 50 年。2030年的ppm水平是 。
从1980年1月=338 ppm，增加量=每年增加1.515 ppm，50年（在此情况下）=1.515×50=75.75，因此2030年预测=338+76=414=选项B 视频😉 https:
Solution 1
This is a time period of 2030 = 50 years, so we can expect the ppm to increase by ppm. Since we started with 338 ppm, we have 76+338=.
2030 - 1980 = 50 years. The ppm level in 2030 is .
From Jan 1980 =338 ppm increase = 1.515 ppm increased / year = 50 yrs (in this case) =1.515 x 50 =75.75 Thus, 2030 prediction = 338 + 76 = 414 = option B Video 😉 https:
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