With a uniform speed, a car covers a distance in 8 hours. Had the speed been increased by 4 km/hr, the same distance could have been covered in 7 hr and 30 min. What is the distance covered?

Question: With a uniform speed, a car covers a distance in 8 hours. Had the speed been increased by 4 km/hr, the same distance could have been covered in 7 hr and 30 min. What is the distance covered?

Solution:
Let the speed of car be x km/hr
Distance = Speed × Time
Distance = 8x km

According to the question,
(x + 4) × 7.5 = 8x
⇒ 7.5x + 30 = 8x
⇒ 8x - 7.5x = 30
⇒ 0.5x = 30
⇒ x = 30/0.5
∴ x = 60 km/hr

Required distance = 8 × 60
= 480 km.