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 1 more than the second pile. How many quarters are in the fourth pile?
p1 = p2 -3
p2
p3 = p2 -2
p4 = p2+1 summed = 20
p2 - 3 + p2 + p2-2 + p2 + 1 = 20
4 p2 -4 = 20
p2 = 6 then p4 = 7