The ratio of A and B is 3:5. The difference between B and A is 2.4. What is B?
甲乙两数的比是3：5，乙数与甲数的差是2.4，乙数是多少．
<gadget id="calculator">5 - 3</gadget>
<output>2</output>

<gadget id="calculator">2.4 / 2</gadget>
<output>1.2</output>

<gadget id="calculator">1.2 * 5</gadget>
<output>6</output>

<result>6</result>