A) 3 : 4
B) 1 : 2
C) 5 : 6
D) 6 : 7
E) None of these
Correct Answer: E
$ \therefore $ Speed of truck $ =\frac{640}{10}=64,km/h $ Distance travelled by car = 640 km and time taken = 8 h
$ \therefore $ Speed of car $ =\frac{640}{8}=80,km/h $ Hence, required ratio = 64: 80 = 4: 5