42 is the answers I the problem
P + s = 200......p = 200 - s
20p + 15s = 3400
20(200 - s) + 15s = 3400
4000 - 20s + 15s = 3400
-20s + 15s = 3400 - 4000
-5s = - 600
s = -600/-5
s = 120 <=== there were 120 standard tickets sold
p + s = 200
p + 120 = 200
p = 200 - 120
p = 80 <=== there were 80 premium tickets sold
(8q)/4 ..................
The appropriate choice is ...
.. <span>A. The initial amount in the account does not change because it is a factor that is independent of both the interest rate and t.
_____
In general, each of the variables in a formula is independent of the others. (Occasionally, you'll see a formula where that is not true, but then the "variable" will likely be indicated as a function of those things it is dependent upon.)</span>