AMC 10A 2010 Problem 3

Tyrone had 97 marbles and Eric had 11 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?

Answer Choices
A. 3
B. 13
C. 18
D. 25
E. 29