Question

Replace A, B, C by suitable numerals.
$$\begin{gathered} \begin{array}{cccc}& C& B& 5\\ -& 2& 8& A\end{array} \\ \overline{\underline{\begin{array}{cccc}& 2& 5& 9\end{array}}} \end{gathered}$$

Answer 1

$5-A=9$
This implies that 1 is borrowed.
We know:
$15-6=9$
∴ $A=6$

$B-5=8$
This implies that 1 is borrowed.
$13-5=8$
But 1 has also been lent
∴$B=4$

$C-2=2$
This implies that 1 has been lent.
∴ $C=5$

∴ $A=6,B=4andC=5$