Question:A and B take part in a 100 m race.A runs at 5 km per hour.A gives B a start of 8 m and still beats him by 8 seconds. The speed of B is :
A 5.15 kmph
B 4.14 kmph
C 4.25 kmph
D 4.4 kmph
/59
+ Answer
B
+ ExplanationA's speed` = (5 xx 5/18)1` m/sec` = 25/18` m/sec.
Time taken by A to cover 100 m` = (100 xx 18/25)`sec = 72 sec.
:. Time taken by A to cover 92 m in (72 + 8) sec or 80 sec.
:. B's speed` = (92/80 xx 18/5)` kmph = 4.14 kmph