Who is the fastest?1Mariam travelled 40 km in 0.5 h.2Ali travelled 52.5 km in 45 min.3Jun Le travelled 180 km in 2 h.4Peter travelled 120 km in 1.5 h.

To determine who is the fastest, we need to calculate the speed of each person. Speed is calculated by dividing the distance travelled by the time taken.

1. Mariam's speed: Distance = 40 km, Time = 0.5 hours Speed = Distance/Time = 40 km / 0.5 h = 80 km/h

2. Ali's speed: Distance = 52.5 km, Time = 45 min. To convert minutes to hours, divide by 60. So, Time = 45/60 = 0.75 hours Speed = Distance/Time = 52.5 km / 0.75 h = 70 km/h

3. Jun Le's speed: Distance = 180 km, Time = 2 hours Speed = Distance/Time = 180 km / 2 h = 90 km/h

4. Peter's speed: Distance = 120 km, Time = 1.5 hours Speed = Distance/Time = 120 km / 1.5 h = 80 km/h

So, Jun Le is the fastest as he has the highest speed of 90 km/h.