A bus leaves a station traveling north at 70 kilometers per hour. Half an hour later a
second bus leaves the same station traveling north at 80 kilometers per hour. How far
from the station will the buses meet?

Respuesta :

Answer:

280 km

Step-by-step explanation:

Given that a bus, say [tex]b_1[/tex], leaves a station traveling north at speed of  70km/hour.

Half an hour later the second bus, say [tex]b_2[/tex],  leaves a station traveling north at speed of  70km/hour.

As, distance = speed x time,

so, the distance traveled by bus [tex]b_1[/tex] in 0.5 hours = 70 x 0.5 = 35 km.

Note that, both the buses are traveling in the same direction and when the second bus leaves the station, the first bus already covered a distance of 35 km.

Let the second bus took [tex]t[/tex] hours to meet the first bus and both the buses meet at a distance of [tex]d[/tex] km from the station.

The distance traveled by the first bus from the station, [tex]d = 35 + 70t[/tex] km

[tex]\Rightarroe t= \frac {d-35}{70}\cdots(i)[/tex]

and the distance traveled by the second bus, [tex]d = 80t[/tex] km

[tex]\Rightarrow t=\frac {d}{80}\cdots(ii)[/tex]

Now, equation the equation (i) and (ii), we have

[tex]\frac {d-35}{70}=\frac {d}{80} \\\\\Rightarrow 8(d-35)=7d \\\\\Rightarrow 8d - 280 = 7d \\\\\Rightarrow 8d-7d=280 \\\\\Rightarrow d = 280 km[/tex]

Hence, both the bus will meet at a distance of 280 km from the station.