Find A using the formula  A = Pe^rt?

P is 30,000 but we might assume it to be US Dollars, but could be bars of gold-pressed Platinum. Also, we don't know if 30,000 is 1 sigfig, 5 sigfigs, or exact, 'assuming' exact USD, but round off to the penny.
A = (30,000)e^(.068×90) = 13645940.8349857
Round to $13,645,940.83

Seems simple enough... where are you having problems?

A = Pe^(rt)

P = 30000
r = 0.068 (turning the percent into a decimal)
t = 90

A = 30000 * e^(0.068 * 90)
A ≈ 13,645,940.83

(In other words, if you invested 30,000 and let it compound continuously at 6.8% for 90 years, it would grow to about 13.6 million.)

They are simply asking you to take those values to plug it into formula and to compute with a calculator for example. We cant go to your place and move your fingers on to the calculator and press the buttons for you. You have to do that on your own.

Btw, 6.8% = 6.8/100 = 0.068

Hello, A = 30,000 e^((6.8/100)90)

A = 30,000e ^ (6.12)
A = 30,000 (454.8646945)
A = 13645940.83 
Hope this helps! 

A = P to the power of e X r to the power of t

You probably used r = 6.8 instead of r = 6.8% = 6.8 /100 

A common mistake, especially when the writers are so cavalier about units. (r should be something PER YEAR to cancel out the units of t.)

A = 30,000 e^((6.8/100)90)
A = 30,000e ^ (6.12) 
A = 30,000 (454.8646945)
A = 13645940.84 (Nearest hundredth). 

A = Pe^(rt)
A = 30000e^[(0.068)(90)]
A = 13,645,940.84 Answer//

 A  = Pe^rt 
 P = 30,000, r = 6.8%, t = 90 years
 A = 30,000 e^(0.068*90) 
 A = 30000 e^(6.12) 
    = 30000*454.8646944995249 
    = 1.3645940834985746*^7
    = 13,645,940.83

A = Pe^(rt)

You are given:

P = 30000, r = 6.8% (or 0.068) and t = 90

Substitute and solve for A:

A = 30000 e^(0.068 * 90)
A = 30000 e^(6.12)
A = 30000(454.86469)
A = $13,645,940.83 (rounded to the nearest penny)