Mom works on the fourth floor. It takes (9/20) minutes to take the elevator from the first floor to the fourth floor. Now my mother has to go down from the fourth floor to the basement to go home by car after get off work. How many minutes does it take for her to take the elevator to the basement? ?
妈妈在四楼上班，坐电梯从一楼到四楼要(9/20)分钟，现在妈妈下班要从四楼下到地下一层去坐车回家，她坐电梯到地下一层要用多少分钟？
<gadget id="calculator">9 / 20</gadget>
<output>9/20 = around 0.45</output>

<gadget id="calculator">4 - 1</gadget>
<output>3</output>

<gadget id="calculator">(9/20) / 3</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">(3/20) * 4</gadget>
<output>3/5 = around 0.6</output>

<result>3/5 = around 0.6</result>