The ticket price for a concert is 40 yuan and 60 yuan. The 60 yuan ticket has 100 seats, and the 40 yuan ticket has 250 seats. The box office revenue is 15,000 yuan. How many people might there be in the audience? (It is known that both types of tickets are sold in tens)
一场音乐会的票价是40元、60元两种，60元的有100个座位，40元的有250个座位，票房的收入是15000元，观众可能有多少人？(已知两种票售出的都是整十数)
<gadget id="calculator">2 * 240</gadget>
<output>480</output>

<gadget id="calculator">750 - 480</gadget>
<output>270</output>

<gadget id="calculator">270 / 3</gadget>
<output>90</output>

<gadget id="calculator">240 + 90</gadget>
<output>330</output>

<result>330</result>