Xiaojun and Xiaohua travel from both places at the same time. Xiaojun travels 12 kilometers per hour, 3 kilometers more than Xiaohua. They meet at a distance of 3 kilometers from the midpoint. How many kilometers is the distance between two places?

Xiaojun and Xiaohua travel from both places at the same time. Xiaojun travels 12 kilometers per hour, 3 kilometers more than Xiaohua. They meet at a distance of 3 kilometers from the midpoint. How many kilometers is the distance between two places?

A: Xiaojun travels 12 kilometers per hour, 3 kilometers more than Xiaohua, so Xiaohua travels 12-3 kilometers per hour = 9 kilometers
The two met at a distance of 3km from the midpoint, so: 3 x 2 / (12-9) = 2 (hours)
So the total distance = 2x (12 + 9) = 42 (km)