The formula for determining exponential functions is expressed as
y = a(1 + r)^n
where
a is the initail value
y is the value after time n
r is the growth rate
From the information given,
a = 285
r = 75/100 = 0.75
n = number of years between 1985 and 2008 = 2008 - 1985 = 23
Thus, we have
y = 285(1 + 0.75)^23
y = 285(1.75)^23
y = 110845988.27
The number of subscribers would be 110845988