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22 Jan 2024, 02:14
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To reduce the strength of a 100% ammonia solution, it is diluted with distilled water in a three-stage process. During each stage, 10% of the container's volume is replaced with distilled water. After the completion of these three stages, what percentage of the container's volume is water?
A. 25%
B. 27.1%
C. 30%
D. 70%
E. 72.9%
A. 25%
B. 27.1%
C. 30%
D. 70%
E. 72.9%
22 Jan 2024, 02:14
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Official Solution:
To reduce the strength of a 100% ammonia solution, it is diluted with distilled water in a three-stage process. During each stage, 10% of the container's volume is replaced with distilled water. After the completion of these three stages, what percentage of the container's volume is water?
A. 25%
B. 27.1%
C. 30%
D. 70%
E. 72.9%
In each stage of dilution, 10% of the container's volume is replaced with distilled water. This means that after the first stage, the solution is 90% ammonia and 10% water. In the second stage, another 10% of the remaining volume is replaced with distilled water, so it becomes 90% of 90% ammonia (81% ammonia) and 19% water. Finally, in the third stage, another 10% of the remaining volume is replaced with distilled water, so it becomes 90% of 81% ammonia (72.9% ammonia) and 27.1% water.
So, after the completion of these three stages, the solution contains 27.1% water.
Answer: B
To reduce the strength of a 100% ammonia solution, it is diluted with distilled water in a three-stage process. During each stage, 10% of the container's volume is replaced with distilled water. After the completion of these three stages, what percentage of the container's volume is water?
A. 25%
B. 27.1%
C. 30%
D. 70%
E. 72.9%
In each stage of dilution, 10% of the container's volume is replaced with distilled water. This means that after the first stage, the solution is 90% ammonia and 10% water. In the second stage, another 10% of the remaining volume is replaced with distilled water, so it becomes 90% of 90% ammonia (81% ammonia) and 19% water. Finally, in the third stage, another 10% of the remaining volume is replaced with distilled water, so it becomes 90% of 81% ammonia (72.9% ammonia) and 27.1% water.
So, after the completion of these three stages, the solution contains 27.1% water.
Answer: B
16 May 2024, 13:05
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I believe some additional details would be beneficial for the clarity of this question.
"During each stage, 10% of the container's volume is replaced with distilled water". It might (might not) be understood that the 10% is of the total container´s volume, not only the ammonia.
If it were of the total, we would be replacing water as well, which wouldn't make much sense. But it would still meet the requirement that we will continue diluting.
"During each stage, 10% of the container's volume is replaced with distilled water". It might (might not) be understood that the 10% is of the total container´s volume, not only the ammonia.
If it were of the total, we would be replacing water as well, which wouldn't make much sense. But it would still meet the requirement that we will continue diluting.
