[Question]: Betty is saving money for a new wallet which costs $100. Betty has only half of the money she needs. Her parents decided to give her $15 for that purpose, and her grandparents twice as much as her parents. How much more money does Betty need to buy the wallet?
[Answer]: In the beginning, Betty has only 100 / 2 = $50. Betty's grandparents gave her 15 * 2 = $30. This means, Betty needs 100 - 50 - 30 - 15 = $5 more.
So the answer is 5.

[Question]: Ravi has some coins. He has 2 more quarters than nickels and 4 more dimes than quarters. If he has 6 nickels, how much money does he have?
[Answer]: Ravi has 6 + 2 = 8 quarters. He has also 8 + 4 = 12 dimes. A nickel is worth 5 cents so Ravi's nickels amount to 6 x 5 = 30 cents. A quarter is worth 25 cents so his quarters amount to 8 x 25 = 200 cents. A dime is worth 10 cents so his dimes amount to 12 x 10 = 120 cents. therefore, Ravi has 30 + 200 + 120 = 350 cents.
So the answer is 350.

[Question]: Adam bought 15 apples on Monday. On Tuesday he bought 3 times that quantity. On Wednesday he bought 4 times the quantity he bought on Tuesday. What is the total quantity Adam bought on these three days?
[Answer]:
On Tuesday, Adam bought 3 * 15 apples = 45 apples. On Wednesday, Adam bought 4 * 45 apples = 180 apples. Adam bought 15 apples + 45 apples + 180 apples = 240 apples on the three days.
So the answer is 240.