This is solved by breaking the equasion down.
2 { 5 [12 + 5 (500 - 100) + 399 ]}
2 { 5 [12 + 5 (400) + 399]}
2 { 5 [12 + 2000 + 399]}
2 { 5 [2411]}
2 {12055}
24110
Is this the answer you were looking for?
Tell you the truth bro I don't know
I believe the first quartile would be 24 and the third would be 8. Sorry if this wasn't correct. I haven't done this in a while.
Hope it helps