Multiple choice

Mia and Ria study in same school, which is 100 m away from their house. They decide to race to the school. Mia starts running when Ria has covered 8 m, but still Mia manages to reach the school 8 seconds before Ria. If Mia runs at a speed of 5 km/hr, what is the speed of Ria?

  1. 4.14 km/hr

  2. 5.14 km/hr

  3. 7.18 km/hr

  4. 9.17 km/hr

  5. 10.6 km/hr
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Mia speed = 5 km/h = 5000/3600 m/s = 25/18 m/s. Time for Mia = 100 / (25/18) = 72 seconds. Ria covered 100 - 8 = 92m. Mia reaches 8s before Ria, so Ria time = 72 + 8 = 80s. Ria speed = 92 / 80 = 1.15 m/s. Convert to km/h: 1.15 * 18/5 = 4.14 km/h.

AI explanation

Mia runs the full 100 m at a speed of 5 km/hr, which is 5000 m per 3600 seconds or 25/18 m/s. Mia's time to reach the school is 100 divided by 25/18, which equals 72 seconds. Ria starts with an 8 m advantage, meaning she needs to run 92 m, and she takes 72 + 8 = 80 seconds to finish the race. Ria's speed is 92 m divided by 80 seconds, equaling 1.15 m/s; converting this to km/hr gives 1.15 multiplied by 18/5, which is 4.14 km/hr.

Keep practicing — related questions