To determine the distance that separates Katie and Christina when Katie stops for gas, we need to calculate the distance Katie has traveled before reaching the gas station.
Katie travels at an average speed of 30 km/hr and has traveled 45 km before stopping for gas. To calculate the time it took for Katie to cover this distance, we can use the formula:
Time = Distance / Speed
Time = 45 km / 30 km/hr = 1.5 hours
Since Katie travels at a constant speed, we can calculate the distance she covers during this time by multiplying her speed by the time:
Distance = Speed × Time
Distance = 30 km/hr × 1.5 hours = 45 km
Therefore, when Katie stops for gas after traveling 45 km, she is 45 km away from the café where she is meeting Christina.