1.

\( \begin{array} \hline \;\;\;3 & A\\ + 2 & 5\\ \hline \;\;B & 2\\ \hline \end{array} \)

We can observe that A+5 gives 2 as the unit's digit to the sum.So it's only possible if A=7.

Now, the sum becomes :

\( \begin{array}
\hline
\;\;\;3 & 7\\
+ 2 & 5\\
\hline
\;\;6 & 2\\
\hline
\end{array}
\)

And we can clearly see that value of B=6.

Therefore we got the values as A=7 and B=6