Question: if the average ( arithmetic mean ) of a and b is 210 , and the average of b and c is 160 , what is the value of a − c ?
A)  − 220
B)  − 100
C) 100
D) 135
E)  it can not be determined from the information given
Correct answer: c
Grade: 6 | Topic: Statistics and Probability | Difficulty: Hard | Standard: 6.SP.B.5