Answer: Convenience sample.
Step-by-step explanation:
Convenience sample is also known as grab or accident or opportunity samples. It is a example of non probability sample that involves selecting of subjects because of the proximity, convenience and accessibility a researcher as to them. This type of samples are not reliable for data gathering when it involves a very large sample space, let's say a global audience.
We have 20% and 60% solutions and need 80 ml of 50%
A) x + y = 80
B) .20x + .60y = (80 * .5)
Multiplying A) by -.2
A) -.2x -.2y = -16 Then adding this to B) we get
.4y = 24
y = 60 ml of 60%
x = 20 ml fo 20%
Source: 1728.com/mixture.htm
He should calmly leave and then report the threat.
