Question

Brian travels a distance at a speed of
12 km/h and returns at 9 km/h. If the
total time taken by him is 3 h 30 min, find
the distance he travelled one way.​

Answer 1

Let D be the unknown distance under the question, in kilometers.

Then the time spent traveling at the speed 12 km/h is D%2F12 hours.

The time spent traveling at the speed 9 km/h is D%2F9 hours.

The total time equation is

D%2F12 + D%2F9 = 31%2F2 hours, or

D%2F12 + D%2F9 = 7%2F2.

Multiply by 36 both sides. You will get

3D + 4D = 7*18, or

7D = 7*18 ====> D = 18 kilometers.

Answer. The one way distance is 18 km.

Answer 2

Answer:

Distance=18km

Step-by-step explanation:

Total time=7/2hr

let distance= D

T1 =D/12..... (1)

T2 =D/9...... (2)

add eq.1 and eq.2

T1+T2=D1/12+D2/9

7/2 = 3D+4D/36

7D=7×18

D=18

Distance=18km of one way