1080 is correct hope this helps.
You can not use either of them because neither of them have a variable= to the eqaution
ex.) y= 3x+25
I don't know if you meant profit or markup but,
take the difference of $80 & $50 = $30
What percent of 50 is 30? It's 3/5 or 60%. So there is a 60% markup on the original price of 50$.
The inequality is t < 55
<em><u>Solution</u></em><em><u>:</u></em>
Given that, To qualify for the championship a runner must complete the race in less than 55 minutes
Let "t" represent the time in minutes of a runner who qualifies for the championship
Here it is given that the value of t is less than 55 minutes
Therefore, "t" must be less than 55, so that the runner qualifies the championship
<em><u>This is represented by inequality:</u></em>
![t](https://tex.z-dn.net/?f=t%3C55)
The above inequality means, that time taken to complete the race must be less than 55 for a runner to qualify
Hence the required inequality is t < 55