Ann and Vincent are driving to an event,
450
kilometers
away. Ann and Vincent drove at a speed of
70
kilometers per hour
for the first
4
hours
. They needed to drive faster for the next
2
hours
to be there on time. At what speed did they have to drive for the last two hours?
To find out the speed they needed to drive for the last two hours, we first need to calculate the distance they covered in the first 4 hours.
Speed = 70 km/hr
Time = 4 hours
Distance = Speed x Time
Distance = 70 km/hr x 4 hr
Distance = 280 km
Now, to find out the remaining distance they need to cover, we subtract the distance covered in the first 4 hours from the total distance.
Total distance = 450 km
Remaining distance = 450 km - 280 km
Remaining distance = 170 km
Since they have 2 hours left to cover the remaining distance, we can calculate the speed they need to drive in the last 2 hours.
Speed = Distance / Time
Speed = 170 km / 2 hr
Speed = 85 km/hr
Therefore, Ann and Vincent needed to drive at a speed of 85 km/hr for the last 2 hours to reach the event on time.