Question

Replace A, B, C by suitable numerals.
$$\begin{gathered} \begin{array}{ccc}& 5& A\\ +& 8& 7\end{array} \\ \overline{\underline{\begin{array}{ccc}C& B& 3\end{array}}} \end{gathered}$$

Answer 1

$$\begin{gathered} A=6 \\ \therefore A+7=6+7=13 \end{gathered}$$

1 is carried over.
$(1+5+8)=14$

1 is carried over.
∴ $B=4$
and $C=1$

∴ $A=6,B=4andC=1$