Which tennis player became the oldest world number one in history on February 18, 2018?
Q1. Which tennis player became the oldest world number one in history on February 18, 2018?
Answer: Roger Federer
Explanation: Roger Federer became the oldest world number one in ATP history on February 18, 2018, at age 36, after winning his 20th Grand Slam at the 2018 Australian Open.