The school plans to buy 75 footballs and basketballs. When buying, replace (2/5) the number of footballs with basketballs. The ratio of the number of footballs to basketballs is 1:4. How many footballs did the school plan to buy? ．
学校准备购买足球和篮球共75个，买的时候把足球个数的(2/5)换成了篮球，那么买的足球与篮球个数的比是1：4，学校原来准备购买多少个足球．
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(1/4) * 75</gadget>
<output>75/4 = around 18.75</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(1/4) * (2/5)</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">(1/4) - (2/5) - (1/10)</gadget>
<output>-1/4 = around -0.25</output>

<gadget id="calculator">1 + (-1/4)</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">(75/4) / (3/4)</gadget>
<output>25</output>

<result>25</result>