[Question]John decided to start rowing around a square lake. Each side of the lake is 15 miles. Jake can row at twice the speed he can swim. It takes him 20 minutes to swim 1 mile. How long, in hours, does it take to row the lake?
[Answer]The perimeter of the lake is 4 * 15 = 60 miles. He swims at a speed of 60 / 20 = 3 mph. So he rows at a speed of 3 * 2 = 6 mph. That means it takes him 60 / 6 = 10 hours to row around the lake. The answer is 10.

[Question]Ten boys brought 15 popsicle sticks each. Twelve girls brought 12 popsicle sticks each. How many fewer popsicle sticks did the girls bring than the boys?
[Answer]The boys brought a total of 10 x 15 = 150 popsicle sticks. The girls brought a total of 12 x 12 = 144 popsicle sticks. Therefore, the girls brought 150 - 144 = 6 fewer popsicle sticks than the boys. The answer is 6.

[Question]How many shirts should Shenny pack for her next vacation if she's planning to use the same shirt when departing on Monday and returning on Sunday and two different shirts each other day?
[Answer]Between Monday and Sunday there are 7 days. If she will be using the same shirt for 2 days then she will need clothes for 7 - 2 = 5 days. Because she wants to use 2 different shirts each of those 5 days then she needs 2 * 5 = 10 shirts. In total she will need 10 shirts between Tuesday and Saturday and 1 shirt for Monday and Sunday = 11 shirts. The answer is 11.

[Question]5,000 people live in a small town. 2,000 males live in that town and the rest of the population are females. Thirty percent of the female population wears glasses. How many females wear glasses?
[Answer]
There are 5,000 - 2,000 = 3,000 females that lives in the town. Since thirty percent of the female population wears glasses, 30 / 100 * 3,000 = 900 females wear glasses. The answer is 900.