In science class, there are 3 cups on each student’s table, one cup is water, one cup is salt, and the other cup is 200 grams of salt water with a salt content of 20%. The teacher asked to change the salt content of the salt water so that the water The mass ratio to salt is 5:1, should I add water or salt? How many grams to add?
科学课上，每个同学的桌面上都放着3只杯子，一杯是水，一杯是盐，还有一杯是含盐率20%的盐水200克，老师要求改变盐水的含盐率，使得水和盐的质量比是5：1，应该添加水还是盐？添加多少克？
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">200 * (1/5)</gadget>
<output>40</output>

<gadget id="calculator">1 / 6</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">200 * (1/6)</gadget>
<output>100/3 = around 33.333333</output>

<gadget id="calculator">40 - (100/3)</gadget>
<output>20/3 = around 6.666667</output>

<gadget id="calculator">1 + 5</gadget>
<output>6</output>

<gadget id="calculator">(20/3) / (1/6)</gadget>
<output>40</output>

<result>40</result>