Four Fours/77/Solutions/1

Puzzle: Four Fours: $77$

Using exactly $4$ instances of the number $4$, the task is to write an expression for $77$, using whatever arithmetical operations you consider necessary.

Solution

$77 = \paren {\dfrac 4 {. \dot 4} }^{\sqrt 4} - 4$

Sources

• 1980: Angela Dunn: Mathematical Bafflers (revised ed.) ... (previous) ... (next): $1$. Say it with Letters: Algebraic Amusements: Four Fours