Hi, this is my first thread on the forum. I wrote the GMAT a 1 month. At the time I was very confident in my quant skills, however since english is not my first language I focused my efforts toward the verbal section. My strategy had mixed results as I scored in the 99th percentile for the verbal section, but in the 48th percentile in the quant part. The problem was that I didn't manage to answer the last questions. So now I am trying to develop strategies to be faster with the math section. How would you go on backsolving this question ?
Each of the 30 boxes in a certain shipment with either 10 pounds or 20 pounds, and the average (arithmetic mean) weight of the boxes in the shipment is 18 pounds. If the average weight of the boxes in the shipment is to be reduced to 14 pounds by removing some of the 20-pound boxes, how many 20-pound boxes must be removed?
A. 4
B. 6
C. 10
D. 20
E. 24
[spoiler]OA: D[/spoiler]
Each of the 30 boxes in a certain shipment with either 10 pounds or 20 pounds, and the average (arithmetic mean) weight of the boxes in the shipment is 18 pounds. If the average weight of the boxes in the shipment is to be reduced to 14 pounds by removing some of the 20-pound boxes, how many 20-pound boxes must be removed?
A. 4
B. 6
C. 10
D. 20
E. 24
[spoiler]OA: D[/spoiler]
