Question

A cyclist cycles 8 km/hr at 15 km/hr and a further 4 km at 20 km/hr. Find the average speed in km/hr.

Answer 1

1st speed of cyclist=15 km/hr
1st Distance=8 km
1st time=15/8 hrs

And

2nd speed= 20km/hr
2nd distance=4 km
2nd time=20/4=5 hrs

now , Average speed=
$now , \: Average \: speed= \frac{total \: distance}{total \: time}$
$= \frac{8 + 4}{ \frac{15}{8} + 5 }$
$\frac{12}{ \frac{15 + 40}{8} }$
$\frac{12}{ \frac{55}{8} }$
$\frac{12 \times 8}{55}$
$\frac{96}{55}$

Answer 2

Answer:16.36

Step-by-step explanation: Average speed = Total distance/Total time

Total distance = 8+4=12

Total time = ((8/15)+(4/20))

Average speed = 12/((8/15)+(4/20))=16.36