I need help I tried asking my family for help too but they also don't understand the question

Question

A car and a bus set out at 5 P.M. from the same point headed in the same direction. The average speed of the car is twice the average speed of the bus. In 2 h, the car is 70 mi ahead of the bus. Find the rate of the car.

Answer 1

Let speed of car be c miles/hr and speed of bus be b miles/hr

Given: c = 2b (speed of car is twice that of bus)

Speed is the rate of change of distance or distance travelled in unit time. If I go at 65 miles/hr, I travel 65 miles in 1 hour.

So if car's speed is c miles/hr, it travels c miles in 1 hour. In 2 hours, car travels 2c miles.

Similarly, bus travels b miles in 1 hour; and 2b miles in 2 hours.

In 2 hours, car travelled 70 more miles than bus. So we have: 2c = 2b + 70

Remember we are given (see above): c = 2b. Hence 2c = c +70 or c = 70. So car's speed is 70 miles/hr.