usain bolt can run 100 m in 9.77s. if he ran this fast at a constant speed, how long will it take him to run a mile

Answer = 157.2 seconds

If 1 mile = 1609.34 metres

Speed he travelled at ... in the 100 metres

100:9.77 = 10.24 metres/second

Then time taken for 1 mile;

Distance/Speed travelled at.

Time taken = 1609.34 : 10.24

Time = 157.2 seconds