Cars A and B are traveling towards each other at the same time from two places 450 kilometers apart, and meet each other after 2 hours. Given that the speed ratio of cars A and B is 5:4, how many hours does it take for car B to complete the journey?
甲、乙两辆汽车同时从相距450千米的两地相向而行，经过2小时相遇．已知甲、乙两辆车的速度比是5：4，乙车行完全程需要多少小时？
<gadget id="calculator">450 / 2</gadget>
<output>225</output>

<gadget id="calculator">5 + 4</gadget>
<output>9</output>

<gadget id="calculator">4 / 9</gadget>
<output>4/9 = around 0.444444</output>

<gadget id="calculator">225 * (4/9)</gadget>
<output>100</output>

<gadget id="calculator">450 / 100</gadget>
<output>9/2 = around 4.5</output>

<result>9/2 = around 4.5</result>