Question 12
Find the units digit of A, where
$A=\underbrace{2\times2\times\cdots\times2}_{50}\times\underbrace{3\times3\times\cdots\times3}_{50}\times\underbrace{4\times4\times\cdots\times4}_{50}$.
Each brace marks 50 copies of its factor.
$A=\underbrace{2\times2\times\cdots\times2}_{50}\times\underbrace{3\times3\times\cdots\times3}_{50}\times\underbrace{4\times4\times\cdots\times4}_{50}$.
Each brace marks 50 copies of its factor.