1. The mean age of the members of a jazz band is 21 . The saxophonist, singer and trumpeter are 19,20 and 21 years old respectively. The other three musicians are all the same age. How old are they?
A 21
B 22
C 23
D 24
E 26
SolUtion
B

The total of the six ages is $6 \times 21=126$. Subtracting 19,20 and 21 leaves 66 for the total of the three unknown ages. Since these are all equal, each is $66 \div 3=22$.