The simple interest formula is: A = P(1 + rt) where P is the original amount of money to be invested at an Interest Rate r% per period for t number of time periods and A is the end balance.
A = 25000(1+(0.02)(4))
A = 25000(1+0.08)
A = 25000(1.08)
25000(1.08) = 27000
So, your ending balance would be $27,000.