The school newly purchased three kinds of balls: basketball, volleyball and football. Among them, the number of basketballs accounts for 1/3 of the total, and the ratio of volleyballs to footballs is 1:5. It is known that 15 volleyballs were purchased, how many of these three types of balls did the school purchase?
学校新购进篮球、排球、足球三种球．其中篮球的个数占总数的(1/3)，排球与足球个数的比是1：5．已知购进排球15个，学校购进这三种球共多少个？
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 - (1/3)</gadget>
<output>2/3 = around 0.666667</output>

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

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

<gadget id="calculator">(2/3) * (1/6)</gadget>
<output>1/9 = around 0.111111</output>

<gadget id="calculator">15 / (1/9)</gadget>
<output>135</output>

<result>135</result>