Consider the question. Brittany, Alex, and Jamy all share 600 marbles divided between them in the ratio 3:5:7. If Brittany gives Alex half of her marbles, what's the total number of marbles that Alex has?
What is the step-by-step reasoning process to arrive at the answer: 260?
The total ratio representing the number of marbles is 3 + 5 + 7 = 15. From the ratio, the fraction representing the number of marbles that Brittany has is 3 / 15, which is equal to 3 / 15 * 600 = 120 marbles. Alex has 5 / 15 * 600 = 200 marbles. If Brittany gives half of her marbles to Alex, Alex receives 1 / 2 * 120 = 60 marbles. After receiving 60 marbles from Brittany, Alex has 200 + 60 = 260 marbles.