Three runners Adam, Ben, and Charles all start at the same time for a $24$ km race, and each of them runs at a constant speed. When Adam finishes the race, Ben is $8$ km behind, and Charles is $12$ km behind. When Ben finishes the race, how far behind is Charles, in km?

6km

Step-by-step explanation:

OK... lets say adam runs at 24 km /hr  finishes in 1 hour

charles is 12 km behind he is only 1/2 way throughmust be running  at 12 km/hr   he will finish in 2 hours

ben is 8km behind    he has run 16 km in one hour     16 km/hr    he will finish in 1  1/2

Charles  done in 2 hours

whne Ben finishes Charles is   still  30 minutes behind x 12/km/hr  = 6 km

it would be 6xy and -16xy.

3

step-by-step explanation:

divide 13.5 by 9 to get the scale factor. it equals 1.5

2 * 1.5 = 3