Six students have the same amount of deposits. If each of them donates 15 yuan to the "Hope Project", the remaining money of the six students is exactly equal to the original savings of the 4 students. How much is the original deposit of each person?
六个同学有同样多的存款，若每人拿出15元捐给"希望工程"后，六位同学剩下的钱正好等于原来4人的存款数，原来每人存款多少元？
<gadget id="calculator">6 - 4</gadget>
<output>2</output>

<gadget id="calculator">6 / 2</gadget>
<output>3</output>

<gadget id="calculator">15 * 3</gadget>
<output>45</output>

<result>45</result>