Question 1001380
Car B -----------x km/h------------ distance = 140 km
car A (x+10) km/h------------------distance = 175 km

time is same for both cars

t=d/r

140/x = 175/(x+10)

140(x+10)=175x

140x+1400= 175x

35x=1400

x= 1400/35

x= 40 km/h => speed of Car B