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This problem trains for: SAT-I, AMC-8, Math Kangaroo 5-6, Math Kangaroo 3-4.

Concrete is a mixture of 1 part cement to 2 parts sand to 6 parts gravel. Approximately how much percent of concrete is gravel?

The total number of parts is 9, out of which 6 are gravel. The percentage x is:

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