Can someone explain to me the answer of this question?

[thayane16]

I appreciate any help

[prakithgre]

let x be the smaller number
A) 2x-x=3 (from this you can find average)
B)sqrt((4/3)*(x^2)) hence x be positive or negative so B is wrong
C)2x=6 so u can use this to find the other and avg is simple
So I guess the answer should be A and C