User contributions
- 13:40, 29 August 2020 (diff | hist) . . (+1) . . 2013 AMC 10A Problems/Problem 21 (→Video Solution by Richard Rusczyk)
- 13:40, 29 August 2020 (diff | hist) . . (+33) . . 2013 AMC 10A Problems/Problem 21 (→Video Solution by Richard Rusczyk)