The ratio of colored balls among A, B, and C is 9:4:2. After A gives B 30 colored balls and also gives C some colored balls, the ratio of A, B, and C’s colored balls is 1: 1:1. How many colored balls did A give C?
甲乙丙三人的彩球数比为9：4：2，甲给了乙30个彩球，也给了丙一些彩球后，甲、乙、丙三人的彩球数的比为1：1：1．甲给了丙多少个彩球？
<gadget id="calculator">9 + 4 + 2</gadget>
<output>15</output>

<gadget id="calculator">15 / 3</gadget>
<output>5</output>

<gadget id="calculator">5 - 4</gadget>
<output>1</output>

<gadget id="calculator">30 / 1</gadget>
<output>30</output>

<gadget id="calculator">5 - 2</gadget>
<output>3</output>

<gadget id="calculator">30 * 3</gadget>
<output>90</output>

<result>90</result>