Question

At 9:00 on Saturday morning, two bicyclists heading in opposite directions pass each other on a bicycle path. The bicyclist heading north is riding 4 km/hour faster than the bicyclist heading south. At 10:15, they are 40 km apart. Find the two bicyclists’ rates.
A. northbound bicyclist = 19 km/h; southbound bicyclist = 15 km/h

B. northbound bicyclist = 18 km/h; southbound bicyclist = 13 km/h

C. northbound bicyclist = 16 km/h; southbound bicyclist = 10 km/h

D. northbound bicyclist = 18 km/h; southbound bicyclist = 14 km/h

Answer 1

Answer:

D Option is the correct one.

Step-by-step explanation:

As,

Distance covered = 40km = 40000m(1k=1000m)

time = 10:15-9:00 = 1:15hours = 75mins

We need to find the rates of the bicyclist in one hour so, for this first we need to calculate the total distance which covered in one hour.

For calculating distance for one hour,

40000/75 = 533.33m/min (means they covered 533.33m distance in one min)

for one hour:

533.33*60= 32000m = 32km

They covered 32km distance in one hour.

Now from the given options D is the correct one because according to give condition north bicyclist covered 4km more that south one. And other reason is we also need to check the sum of distance covered by the both cyclist which must be equal to 32km.

So for A,

Sum = 19 + 15 =34 (wrong not equal to 32)

For B,

Sum = 18 + 13 = 31 (wrong)

For C,

Sum = 16 + 10 = 26(wrong)

For D,

Sum = 18 + 14 = 32 (Right)

And second distance b/w both distance is 4km.

18-14 = 4(Right)

So, D option is the right one.

I hope it will help you.