Answer:
15.

16. 10 ml of 20% saline and 40 ml of 10% saline
Step-by-step explanation:
A chemist takes x ml of 20% saline and y ml of 10% saline. In total, he takes
x + y ml that is 50 ml, so

There are
ml of salt in x ml of 20% saline and
ml of salt in 10% saline. There are
ml of salt in 50 ml of 12% saline. Thus,

15. We get the system of two equations:

16. Solve this system. From the first equation:

Substitute it into the second equation:

I think the last two are correct.
Hope it helps
Answer: Interviewer-induced bias
Step-by-step explanation:
The example given in the question illustrates the Interviewer-induced bias. This occurs when the situation created by the interviewer is such that the respondent will have to give the kind f answer that the interviewer wants to hear.
For example, in the question, we can deduce that the interviewers told the interviewees that they won't be investigated and the gave bias replies based on that.
Answer:
See explanation, and comment for more details!
Step-by-step explanation:
10. The perimeter of any shape is the sum of the length of the sides, which means that the perimeter of this triangle is x+y+z.
11. Since this is a right triangle, the two legs form the height and base. The area of this triangle is therefore x*y/2.
12.
a. x=3, y=4, z=5
b. 
c.
Hope this helps!