During a TYPICAL week, the store sells two 13-inch laptops for every 15-inch laptop.
Let x = the number of 15-inch laptops TYPICALLY sold each week
So, 2x = the number of 13-inch laptops TYPICALLY sold each week

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.
So, 50% of 2x = the number of 13-inch laptops sold each week during the HOLIDAYS
In other words, x = the number of 13-inch laptops sold each week during the HOLIDAYS

Also, (3)(x) = = the number of 15-inch laptops sold each week during the HOLIDAYS

If the store sells 600 laptops per week during the holiday season...
We can write: x + (3)(x) = 600
Simplify: 4x = 600
Solve: x = 150

Since x = the number of 13-inch laptops sold each week during the HOLIDAYS, we know that 150 13-inch laptops were sold each week during the HOLIDAYS
600 - 150 = 450, so 450 15-inch laptops were sold each week during the HOLIDAYS

....how many more 15-inch laptops than 13-inch laptops are sold?
450 - 150 = 300

Answer: D

Cheers,
Brent
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initial ratio is 2:1

then during holiday the rration becomes 1 : 3

so total sale = 600 = 1x + 3x

4x = 600
x =150..

13 inch = 150..
15 inch = 450

450- 150 = 300
ans D

It's D. 300.

300 15-inch laptops will be sold more than 13-inch laptops if the store sells 600 laptops per week during the holiday season.

Initial ratio of 13 and 15 inches: 2: 1

Holiday ratio: 1 : 3

Total : 600 sold: 150 : 450

Difference: 450 - 150 = 300

Answer D
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