A can run 4 times as fast as B and gives B a start of 63 m. How long should the race course be so that A and B might reach in the same time?  Choose the correct choice from the following options.
A) 70 m  B) 60 m  C) 80 m  D) 65 m  E) 84 m
Speed of A:Speed of B=4:1   means in a race of 4m A gains 3m.   then in a race of 63m he gains 63*(4/3)   I.e 84m   ANSW84 mR:84 m
<result>E</result>
A can run 4 times as fast as B and gives B a start of 63 m. How long should the race course be so that A and B might reach in the same time?