There is a total of 20 quarters stacked in four piles. The first pile has 3 fewer than the second pile. The second pile has 2 more than the third pile. The fourth pile has twice as many as the second pile. How many quarters are in the fourth pile?
I can write an equation for each relationship using x as the number of quarters in the second pile. The first pile has 3 fewer than the second pile, so the first pile has x - 3 quarters. The second pile has 2 more than the third pile, so the third pile has x - 2 quarters. The fourth pile has twice as many as the second pile, so the fourth pile has 2x quarters. The total number of quarters is 20, so I can add up the expressions for each pile and set them equal to 20. This gives me the equation x - 3 + x + x - 2 + 2x = 20. To solve for x, I can combine like terms and simplify the equation. I get 5x - 5 = 20. Adding 5 to both sides, I get 5x = 25. Dividing both sides by 5, I get x = 5. This means that the second pile has 5 quarters. To find the number of quarters in the fourth pile, I can multiply x by 2. So the fourth pile has 2x = 2 * 5 = 10 quarters.

