and B set off from A and B at the same time respectively, and the walking speed ratio of A and B is 7:5. If they are traveling in the same direction, they will meet after 0.5 hours; if they are traveling in the same direction from A to B, how many hours will it take for A to catch up with B?
甲、乙分别由A，B两地同时出发，甲、乙两人步行的速度比是7：5．如果相向而行，那么0.5时后相遇；如果按从A到B的方向同向而行，那么甲追上乙需要多少小时？
<gadget id="calculator">7 + 5</gadget>
<output>12</output>

<gadget id="calculator">7 - 5</gadget>
<output>2</output>

<gadget id="calculator">0.5 / 2</gadget>
<output>0.25</output>

<gadget id="calculator">12 * 0.25</gadget>
<output>3</output>

<result>3</result>