A car travells the first 1/3 of certain distance with a speed of 7km/hr the next 1/2 distance witha a speed of 12 km/hr, and the last 1/4 distance with a speed of 16 km/hr. the average speed of the carfor the whole journey is?  Answers
A) 9.53km/hr
B) 56.89km/hr
C) 8.96km/hr
D) 7.96km/hr
E) 25.86km/hr
Let the whole distance travelled be x km   and the average speed of the car for he whole journey be y km/hr   then (x/3)/7+(x/2)/12+(x/4)/16=x/y   x/21+x/24+x/64=x/y   y=9.53km/hr   9.53km/hrnswer(9.53km/hr)
<result>A</result>
A car travells the first 1/3 of certain distance with a speed of 7km/hr the next 1/2 distance witha a speed of 12 km/hr, and the last 1/4 distance with a speed of 16 km/hr. the average speed of the carfor the whole journey is?