单选题
What is the average (arithmetic mean) of 330, 360, and 390?
(A) 360
(B) 3177
(C) 310 + 320 + 330
(D) 327 + 357 + 387
(E) 329 + 359 + 389
【正确答案】
E
【答案解析】To find the average of three numbers, divide their sum by 3: [*]Now use the distributive law and divide each term in the numerator by 3: [*] =329+359+ 389.