Gordon H. answered  10/31/15
Tutor
                    
    New to Wyzant
            Math tutor for high school and college
Meeka,
       Using US measurement conversion there are 48 teaspoons in a cup. 
Next, we set up a proportion to find the number of ounces in 2 1/2 teaspoons.
2 1/2 teaspoons/48 teaspoons = x ounces/3 ounces
If we multiply both sides of the equation by 3, we get
7 1/2 /48 = x
So, x = 0.15625 ounces.  As a fraction, this would be 5/32 ounce.