There are four natural numbers, the ratio of A to B is 3:5, the ratio of B to C is 4:7, the sum of A and B is 160, what is B?
有四个自然数，甲数与乙数的比是3：5，乙数与丙数的比是4：7，甲乙两数的和是160，则乙数是多少．
<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">1 + (3/5)</gadget>
<output>8/5 = around 1.6</output>

<gadget id="calculator">160 / (8/5)</gadget>
<output>100</output>

<result>100</result>