There are several little white rabbits and little gray rabbits each. If 6 little white rabbits and 4 little gray rabbits are put in a cage, there are 9 more little white rabbits, and the little gray rabbits are just put out; if 9 little white rabbits and 4 little gray rabbits are put in a cage , The little white rabbits just finished, and there are 16 more little gray rabbits. So how many little white rabbits and little gray rabbits are there?
小白兔和小灰兔各有若干只．如果6只小白兔和4只小灰兔放到一个笼子中，小白兔还多9只，小灰兔恰好放完；如果9只小白兔和4只小灰兔放到一个笼子中，小白兔恰好放完，小灰兔还多16只．那么小白兔和小灰兔共有多少只．
<gadget id="calculator">6 * 15</gadget>
<output>90</output>

<gadget id="calculator">90 + 9</gadget>
<output>99</output>

<gadget id="calculator">15 * 4</gadget>
<output>60</output>

<gadget id="calculator">99 + 60</gadget>
<output>159</output>

<result>159</result>