The ratio of the numbers A and B is 5:4. The number A minus the number B is 10. What is the number B?
甲乙两数的比是5：4，甲数减乙数得10，乙数是多少
<gadget id="calculator">5 - 4</gadget>
<output>1</output>

<gadget id="calculator">10 / 1</gadget>
<output>10</output>

<gadget id="calculator">10 * 4</gadget>
<output>40</output>

<result>40</result>