Multiple choice

Points A and Bare 80 km. apart from each other on a highway. A car starts from A and another from B at the same time. If they move in the same direction, they meet in 8 hours and if they move in opposite directions, they meet in one hour and twenty minutes. Find the speeds of the two cars

  1. 55 km/h & 35 km/hr

  2. 50 km/h & 35 km/hr

  3. 70 km/h & 60 km/hr

  4. 35 km/h & 25 km/hr
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Let speeds be x and y. Same direction: 80 / (x-y) = 8 => x-y = 10. Opposite direction: 80 / (x+y) = 4/3 => x+y = 60. Solving: 2x = 70 => x = 35, y = 25.

AI explanation

Let the speeds of the two cars be x and y. When they move in the same direction, their relative speed is x minus y, so x minus y equals 80 divided by 8, which is 10. When they move in opposite directions, their relative speed is x plus y, so x plus y equals 80 divided by 1.33, which is 60. Solving the equations x minus y equals 10 and x plus y equals 60 gives the speeds as 35 km/h and 25 km/h.

Keep practicing — related questions