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Mathematics>Standard Multiple Choice

Read the following SAT test question and then click on a button to select your answer.

Anna spent 3 hours in her garden planting 6 rosebushes. To plant a rosebush, she first dug a hole then refilled the hole with the root ball, dirt, and compost. She spent twice as long digging the hole for each plant as she did refilling it. Which of the following could be used to find the number of minutes, m, Anna spent digging each hole?

A.6m+6(2m)=3
B.6m+6(m/2)=3
C.6m+6(2m)=180
D.6m+6(m/2)=180

答案和解析

答案：D

解析：

Option D is correct. Since m represents the number of minutes spent digging a hole for a single rosebush, then Anna spent 6m minutes digging holes for all 6 rosebushes. Since Anna spent half the time refilling each hole as digging each hole, she spent m/2 minutes refilling each hole and 6(m/2) minutes refilling all the holes.