There was a major collision of an asteroid with the moon in

Question

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Question: There was a major collision of an asteroid with the Moon in medieval times. It was described by monks at Canterbury Cathedral in England as a red glow on and around the Moon.

A- How long after the asteroid hit the Moon, which is 3.84e⁺⁰⁵ km away, would the light first arrives on Earth?

I want tutor help to solve the above question. Thanks.