GWD19-32^-^

谢沁薇

Q32:

A certain list consists of 3 different numbers.  Does the median of the 3 numbers equal the average (arithmetic mean) of the 3 numbers?

(1)   The range of the 3 numbers is equal to twice the difference between the greatest number and the median.

(2)     The sum of the 3 numbers is equal to 3 times one of the numbers.

key is D ?... why 2 is correct??

  THANKS

谢沁薇

xiexie !

yaoyao99

Let the list be {a, b, c} where a > b > c so median = b
question: (a+b+c)/3 ? b
conditon 2: a+b+c = 3* one of the numbers. 
=> 3*a > a+b+c (because a>b>c)
=> 3*c < a+b+c (because c<b<a)
"one of the numbers" has to be b => (a+b+c)/3 = b

谢沁薇

了解！谢谢^-^

jingle0915

了解！谢谢^-^