Zhang Xiaohong reads a story book. After reading some of it, the ratio of what she has read to the rest is 1:4. She read another 30 pages, and now she has read 60% of the whole book. How many pages does this storybook have?
张小红看一本故事书，看了一些后，已看的与剩下的比是1：4，又看了30页，此时已看了全书的60%．这本故事书共多少页？
<gadget id="calculator">60 / 100</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">1 + 4</gadget>
<output>5</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(3/5) - (1/5)</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">30 / (2/5)</gadget>
<output>75</output>

<result>75</result>