The median number of students in each music class is 19 people find the missing value 16, ? , 24, 17, 20, 21

Arrange the numbers from least to greatest
16 17 ? 20 21 24
Median is the number in the middle, since there is 6 numbers the the median is the missing value + 20.
To find the missing value multiply 19 x 2 = 38
Now subtract 38 - 20= 18
The missing value is 18
The median is 18+20= 38... 38/2= 19

Answer d; a supplementary angle = 180°, so if that angle = 150°, y would = 30°.