Question

A person walks downhill at 10 km/h, uphill at 6 km/h and on the plane at 7.5 km/h. If the person takes 3 hours to go from a place A to another place B, and 1 hour on the way back, the distance between A and B is ?
(15km is the answer, I'll give brainliest to the one who explains it)​

Answer 1

Answer:

15 km

Step-by-step explanation:

Attempt: If he walked XkmXkm downhill, YkmYkm uphill, and ZkmZkm on a plane, we get

Xkm10km/h+Ykm6km/h+Zkm7.5km/h=3→(1)Xkm10km/h+Ykm6km/h+Zkm7.5km/h=3→(1)

and

Xkm6km/h+Ykm10km/h+Zkm7.5km/h=1→(2)Xkm6km/h+Ykm10km/h+Zkm7.5km/h=1→(2)

We are supposed to find distance between A and B, that is, X+Y+ZX+Y+Z. Adding those equations and simplifying, we get 2(X+Y)+Z=302(X+Y)+Z=30