12. John worked at a bookstore for two weeks. The second week he earned 20 percent more than he did the first week. If he earned $300 the second week, how much did he earn the first week?
Answer: B
John earned $250 in the first week.
To determine John's earnings in the first week, we can set up an equation based on his earnings in the second week being 20 percent more than the first week. If he earned $300 in the second week, then the amount he earned in the first week is calculated as $300 divided by 1.2, which equals $250.
A) 240
Option A is incorrect because if John earned $240 in the first week, then a 20 percent increase would result in earnings of $288 in the second week, not the $300 he actually earned.
B) 250
Option B is correct as it accurately reflects that if John earned $250 in the first week, a 20 percent increase would lead to earnings of $300 in the second week ($250 * 1.2 = $300).
C) 280
Option C is incorrect because if John earned $280 in the first week, a 20 percent increase would make his second week earnings $336, which does not match the $300 he earned.
D) 380
Option D is incorrect since if John earned $380 in the first week, a 20 percent increase would result in earnings of $456 in the second week, far exceeding the $300 he actually earned.
Conclusion
The calculation confirms that John earned $250 in the first week, as this amount correctly leads to his second week earnings of $300 when accounting for the 20 percent increase. All other options fail to align with the earnings structure provided in the question, demonstrating their inaccuracy.