Now according to our question the center pay her 'b' dollars and after she paid a fee of .25 dollars she was left with 3.20 dollars.
So
[tex]\begin{gathered} b-0.25=3.20 \\ b=3.20+0.25 \\ b=3.45 \\ So\text{ value of b is 3.45 dollars.} \end{gathered}[/tex]