In an exam, A, B, C, and D are graded as A, B, C, and D respectively. One number is removed each time, and the average of the remaining three numbers is calculated. Four times like this, four numbers are obtained: 89 , 90, 91, 93, what is the lowest score among the four numbers?
一次考试，甲、乙、丙、丁四人成绩分别为A、B、C、D，每次去掉一个数，将其余3个数求平均数，这样计算四次，得到这样4个数：89、90,91、93，则四个数中成绩最低是多少分．
<gadget id="calculator">89 * 3</gadget>
<output>267</output>

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

<gadget id="calculator">91 * 3</gadget>
<output>273</output>

<gadget id="calculator">93 * 3</gadget>
<output>279</output>

<gadget id="calculator">267 + 270 + 273 + 279</gadget>
<output>1_089</output>

<gadget id="calculator">1_089 / 3</gadget>
<output>363</output>

<gadget id="calculator">363 - 279</gadget>
<output>84</output>

<result>84</result>