Answer: 

Step-by-step explanation:
- A null hypothesis is a hypothesis where a researcher generally try to disprove, it says that there is no statistically significant relationship between the two variables .
- An alternative hypothesis says that there is a statistical significance between two variables.
Claim 1. : Mean age of online dating service users is 40 years.
i.e.
, since it has equals sign so we take this as null hypothesis.
Claim 2. : Mean age of online dating service users is not 40 years.
⇒ Null Hypothesis : 
Alternative hypothesis : 
It has to be b because none of the others are correct.
Explanation: Just like any of your two-step equations,
in this inequality, start by isolating the x term which in this
case is -3x by subtracting 5 from both sides.
That leaves you with -3x < -24.
To get x by itself, divide both sides by -3 but watch out.
When you multiply or divide both sides of an inequality by a
negative number, you must switch the direction of the inequality sign.
So we have x < 8 and put your final answer in
set notation and it look like this → {x: x < 8}.