The average of the first 6 positive multiples of 6 will be

Explanation

The number of first 6 positive multiples of 6 = 6, 12, 18, 24, 30, 36 Average = $$ \frac{6 + 12 + 18 + 24 + 30 + 36}{6} $$ = $$ \frac{126}{6} $$ = 21