Usain Bolt ran 19:30 with a -0.9 second head wind if.....?

Question

Usain Bolt ran 19:30 with a -0.9 second head wind.If he had the tailwind that Michael Johnson had when he broke it (+1.8 seconds), what would his time have been??? Im guess 18 something

Answer 1

Do the math. It would be 19.03.