Algebra
posted by Ruth .
Students in an English class took a final exam. They took equivalent forms of the exam at monthly intervals thereafter. The average score S(t), in percent, after t months was found to be given by
.
a) What was the average score when they initially took the test, t = 0?
S(t) =28  20 log (t+1), t>(greater than) 0

You say your equation is not valid for t=0. Why not?
I would assume S(0) = 28  20log1 = 28
Note that negative scores are possible for n>26, which seems unlikely