1) Since it was 0 years when the college opened, we put x=0 and we get
T=12000
2) 0.03%
3) From 1990 to 2020, it is 30 years. Thus, x=30.
T=12000*(1.03)^30
For calculations for the 2nd point, refer to the picture.
Hope this helps!
For future whenever you solve these type, just know that x is a variable and tree have to insert out own value for x according to the questions’s demand.