Question

With a uniform speed, a car covers the distance in 8 h. Had the speed been
increased by 4 km/h, the same distance could have been covered in 7 h. What is the distance covered?
(1) 640 km
(2) 480 km
(3) 420 km
(4) Cannot be determined​

Answer 1

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=300.5=60 km/hr

Required distance :

= 8 × 60

= 480 km