A manuscript has 210 pages, the efficiency of type A printer is 5 pages/minute, and the efficiency of type B printer is 9 pages/minute. So, this manuscript is printed by two printers at the same time, how many minutes can it be printed?
一份稿件有210页，A型打印机效率是5页/分，B型打印机效率是9页/分．那么，这份稿件由两台打印机同时打印，几分钟可印完？
<gadget id="calculator">5 + 9</gadget>
<output>14</output>

<gadget id="calculator">210 / 14</gadget>
<output>15</output>

<result>15</result>