(d) Let the distance between two terminus be x km.
Now, relative distance travel by the buses before they meet for the first time = x km
Similarly, relative distance travelled after first and second meet = 2x
Now, bus originating from terminus A travels 7 km before the first meet.
Hence it should travel 2 × 7 = 14 km after first meet and before second meet.
Hence total distance travelled before Second meet = 7 + 14 = 21 km
Now, second meet occurs at 4 km from terminus B.
Hence, total distance travelled by bus starting from terminus A = (x + 4) km = 21
∴x = 17 km
Now, one bus travels 34 × 5 = 170 km a day
Cost of running one bus = 170 × 20 =Rs . 3400
∴ Cost of running two buses
= 2 × 3400 = Rs. 6800