A certain list consists of 21 different numbers. If n is in the list and n is 3 times the average (arithmetic mean) of the other 20 numbers in the list, then n is what fraction of the sum of the 21 numbers in the list? Select the correct option:
A) 1/20
B) 1/6
C) 1/5
D) 4/21
E) 3/23
series : a1, a2....a20,n   sum of a1+a2+...+a20 = 20*x (x = average)   so, n = 3*x   Hence, a1+a2+..+a20+n = 23x   So, the fraction asked = 3x/23x =3/23   Answer 3/23
<result>E</result>
A certain list consists of 21 different numbers. If n is in the list and n is 3 times the average (arithmetic mean) of the other 20 numbers in the list, then n is what fraction of the sum of the 21 numbers in the list?