A field density test is 116.5 pcf and the Proctor maximum dry density is 124.0 pcf. What percent compaction is achieved?
Correct Answer
A) 94.0%
Percent compaction is 116.5 / 124.0 x 100 = 94.0%.
Why This Is the Correct Answer
Percent compaction is 116.5 / 124.0 x 100 = 94.0%.
Why the Other Options Are Wrong
Option B: 90.0%
compaction percent, choice a: 90.0% backs into 2,232 when divided by 5 / 124; the accepted setup gives 2,331.2 on that same base.
Option C: 96.5%
compaction percent, choice b: 96.5% adds an extra unstated add-on/subtraction; the numeric gap is 2.5.
Option D: 106.4%
compaction percent, choice c: 106.4% is produced by 124.0 / 116.5. The error is using that partial/alternate setup.
Memory Technique
Store compaction percent with its last math move; nearby answers are usually unfinished versions of 94.0%.
Reference Hint
Open Pipe and Excavation Contracting, 2011; use by topic index - bedding / backfill / compaction to confirm that Percent compaction is 116.5 / 124.0 x 100 = 94.0%.
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