Step-by-step reasoning process: 20 of 50 marbles are white so there are 50 - 20 = 30 red and blue marbles. The number of red marbles and blue marbles is the same, so there are 30 / 2 = 15 of each color. The difference between the number of white marbles and blue marbles is 20 - 15 = 5. Double the difference is 5 * 2 = 10 marbles. 10 marbles are removed to leave 50 - 10 = 40 marbles.
The question and answer:
Question and answer: There are 50 marbles in a box which has a mixture of white, red and blue marbles. There were originally 20 white marbles and an equal number of red and blue marbles. Jack removes a number of marbles equal to double the difference between the number of white marbles and the number of blue marbles. How many marbles are left in the box?
The answer is 40

Step-by-step reasoning process: Find the price of each group of fruit. 12 apples * $2 per apple = $24. 4 bananas * $1 per banana = $4. 3 oranges * $4 per orange = $12. $24 + $4 + $12 = $40 in total that was spent. 12 + 4 + 4 = 20 total fruits bought. $40 / 20 fruits = $2 per fruit.
The question and answer:
Question and answer: Marcia wants to buy some fruit. Apples cost $2, bananas cost $1, and oranges cost $3. If Marcia buys 12 apples, 4 bananas and 4 oranges, what is the average cost of each piece of fruit in dollars?
The answer is 2

Step-by-step reasoning process: The third and fourth day contributed 6 + 18 = 24 inches to the depth of the snowdrift. Therefore, the size of the snowdrift after half was melted on the second day, but before the snowfall on the third and fourth day, was 34 - 24 = 10 inches. If the size of the drift on the second day, after half of the snow had melted, was 10 inches, then the depth of the original drift created on day 1 was 2 * 10 = 20 inches deep.
The question and answer:
Question and answer:
A big snowstorm caused a large amount of snow to fall onto Grandpa's farm, and the wind caused the snow to pile up into a drift. But on the second day, it warmed up enough that half of the snowdrift melted. The third day, it snowed again, adding another 6 inches of snow onto the snowdrift. On the fourth day, another 18 inches of snow fell onto the snowdrift. If the snowdrift was 34 inches deep at the end of the fourth day, how deep in inches was the drift at the end of the first day?
The answer is 20