A policeman follows a thief is 800 metre ahead of him. If they run at the speed of 8 km per hour and 7 km per hour respectively, How long the policeman take to catch up with the thief?

Asked by Pradeep | 20th Aug, 2018, 09:59: PM

Expert Answer:

begin mathsize 16px style Relative space speed space of space the space policeman space with space respect space to space the space thief space equals space 9 space minus space 8 space equals space 1 space space km divided by hr.
800 space straight m space equals space 800 over 1000 space equals space 4 over 5
Therefore comma space time space taken space by space the space policeman space to space catch space the space thief space equals space open parentheses 4 over 5 close parentheses divided by 1 space equals space 4 over 5 space hr space
Distance space run space by space the space thief space space equals space 8 space cross times space 4 over 5 space equals space 32 over 5 km space equals space space 32 over 5 cross times space 1000 equals space 6400 space straight m

end style

Answered by Yasmeen Khan | 23rd Aug, 2018, 02:13: PM

Queries asked on Sunday & after 7pm from Monday to Saturday will be answered after 12pm the next working day.