[Question]Aliyah has 10 more phones than her sister Vivienne. If Vivienne has 40 phones, and the two sisters sell their phones at $400 each, calculate the total amount of money they have together?
[Answer]The total amount of money that Vivienne gets from selling her phones is 40 * 400 = 16000. Since Aliyah has 10 more phones than Vivienne, she has 40 + 10 = 50 phones. When she sells her phones, Aliyah receives 50 * $400 = $20000. Together they have $20000 + $16000 = $36000. The answer is 36000.

[Question]Jason bought a new bookcase that can hold a maximum of 80 pounds of weight. Jason has 70 hardcover books that each weigh half a pound, 30 textbooks that each weigh 2 pounds, and 3 knick-knacks that each weight 6 pounds. How many pounds over the bookcase's weight limit is this total collection of items?
[Answer]First find the total weight of the hardcover books: 70 books * .5 pound / book = 35 pounds. Then find the total weight of the textbooks: 30 books * 2 pounds / book = 60 pounds. Then find the total weight of the knick - knacks: 3 knick - knacks * 6 pounds / knick - knack = 18 pounds. Then find the total weight of all the items: 35 pounds + 60 pounds + 18 pounds = 113 pounds. Then subtract the bookcase's weight limit: 113 pounds - 80 pounds = 33 pounds. The answer is 33.

[Question]Janet starts driving across a lake in a speedboat going 30 miles per hour. Her sister follows in a sailboat that has a speed of 12 miles per hour. If the lake is 60 miles wide, how long does Janet have to wait on the other side for her sister to catch up?
[Answer]First find how long it takes Janet to cross the lake: 60 miles / 30 miles / hour = 2 hours. Then find how long it takes her sister to cross the lake: 60 miles / 12 miles / hour = 5 hours. Then subtract Janet's travel time from her sister's travel time to find the difference: 5 hours - 2 hours = 3 hours. The answer is 3.

[Question]Karen's class fund contains only $10 and $20 bills, which amount to $120. The number of $10 bills is twice as many $20 bills. How many $20 bills do they have in their fund?
[Answer]
If n is the number of $20 bills then 2n is the number of $10 bills. So the equation will be $10(2n) + $20n = $120. By combining like terms, the equation becomes 40n = 120. So, the value of n which represents the number of $20 bills is 120 / 40 = 3. The answer is 3.