Question

The maximum value of n such that 2^n  divides 21! is ________

Answer 1

the answer is the greatest integer function of the successive powers of 2 that divide 21.
therefore n=[21/2]+[21/4]+[21/8]+[21/16]+[21/32]+...till infinity
so n=10+5+2+1=18

Answer 2

Answer:

$\huge\star\underline{\mathtt\color{aqua}{⫷❥A} \mathfrak\color{yellow}{N~ }\mathfrak\color{blue}{S} \mathbb\color{purple}{W} \mathtt\color{orange}{E} \mathbb\color{red}{R⫸}}\star\:⋆$Diagonal of the rhombus and it's side form an angle of 70 degrees. What's the acute angle?