\[ \begin{array} {ccccc} \large & & & \color{red}H & \color{green}A & \color{blue}D\\ \large & & & & \color{red}H & \color{green}A\\ \large + & & & & & \color{red}H \\ \hline \large & & & \color{green}A & \color{red}H & \color{green}A \end{array} \]
If each letter represents a different nonzero digit, what must \(\color{blue}D\) be?
This is the hardest cryptogram we've challenged you with so far, but they can get much harder yet!
by Brilliant Staff
