The fast train goes from A to B, and the slow train goes from B to A. The two trains start at the same time and drive toward each other. It is known that the fast train travels 90 kilometers per hour, and the slow train travels 60 kilometers per hour. The two vehicles meet at a distance of 45 kilometers from the midpoint of A and B after a certain time. How many kilometers is the meeting place from place B?
快车从甲地开往乙地，慢车从乙地开往甲地，两车同时出发，相向而行．已知快车每时行90千米，慢车每时行60千米，两车开出后经过若干时在距甲、乙两地中点45千米处相遇．相遇地点距乙地有多少千米？
<gadget id="calculator">90 - 60</gadget>
<output>30</output>

<gadget id="calculator">2 / 30</gadget>
<output>1/15 = around 0.066667</output>

<gadget id="calculator">45 * (1/15) * 60</gadget>
<output>180</output>

<result>180</result>