There are 120 red and white balls in the box. After reducing the red balls by 30% and the white balls by 40%, the total number of red balls and white balls becomes 79. How many white balls were there originally?
盒子中有红球和白球共120个，将红球减少30%，白球减少40%后，红球和白球总个数变成79个，白球原来有多少个？
<gadget id="calculator">30 / 100</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">120 * (3/10)</gadget>
<output>36</output>

<gadget id="calculator">120 - 36 - 79</gadget>
<output>5</output>

<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - 1 - (3/10)</gadget>
<output>-3/10 = around -0.3</output>

<gadget id="calculator">(2/5) + (-3/10)</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">5 / (1/10)</gadget>
<output>50</output>

<result>50</result>