2010 AMC 10A Problems/Problem 3
Contents
Problem 3
Tyrone had marbles and Eric had marbles. Tyrone then gave some of his marbles to Eric so that Tyrone ended with twice as many marbles as Eric. How many marbles did Tyrone give to Eric?
Solution 1
Let be the number of marbles Tyrone gave to Eric. Then, . Solving for yields and . The answer is .
Solution 2
Since the amount of balls Tyler and Eric have a specific ratio when Tyler give some of his balls to Eric, we can divide the balls to their respective ratios. Altogether, they have balls, or balls, and it does not change when Tyler give some of his to Eric, since none are lost in the process. After Tyler give a few of his balls away, the ratio between the balls is , meaning that together added up is . The two numbers add up to and we divide by , and outcomes . This is the amount of balls Eric has, and so doubling that results in the amount of balls Tyler has, which is . is , and is , thus proving our statement true.
See Also
2010 AMC 10A (Problems • Answer Key • Resources) | ||
Preceded by Problem 2 |
Followed by Problem 4 | |
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All AMC 10 Problems and Solutions |
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