Brian wants to build a ramp that leads to a storeroom 5 meters above the ground. he wants the ramp to be 10 meters long. what should the angle of elevation of the ramp be?

There are several information's of immense importance already given in the question. Based on those given information's the answer can be easily deduced. Let us now focus on the problem in hand.
Height at which the storeroom is located = 5 meters
Length of the ramp = 10 meters
Let us assume the angle = x
Then
Sin(x) = 5/10
          = 1/2
Sin(x) = Sin(30)
x = 30 degree
From the above deduction, we can conclude that the ramp should have an angle of elevation of 30 degrees.

Your cleary not see the answer is 25