Answer:
D.
Step-by-step explanation:
First try to eliminate answers.
You have to work between 30 and 40 hours to get 1565.
It's not A or B.
Now, you can see that the choices are 31, and 35
1565 is only 15 more than 1550.
It's 31.
The answer to 2y+7(y-3)=60 is y=9
89kg in stones would be 12.598 stones
If we rearrange the given data set from lowest to highest, we have

The minimum is 3.
The first quartile is the average of 6 and 7, which is 6.5
The median is the average of 8 and 10 which is 9.
The third quartile is the average of 12 and 15 which is 13.5.
The maximum is 18.