A computer store sells two sizes of laptops, 13-inch and 15-inch. During a typical week, the store sells two 13-inch laptops for every 15-inch laptop. However, during the holiday season, the number of 13-inch laptops sold decreases by 50 percent, and the number of 15-inch laptops sold triples. If the store sells 600 laptops per week during the holiday season, how many more 15-inch laptops than 13-inch laptops are sold?

A. 100
B. 150
C. 200
D. 300
E. 400
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