what divided by what equals 21

Question

very hard to decide what divided by what equals 21

Answer 1

There are infinitely many solutions to this.

 

21n divided by n equals 21, for any n ≠ 0.

Answer 2

Look at multiples of 21:

 

21(2) = 42 ... 42/2 = 21

21(3) = 63 ... 63/3 = 21

 

You can continue this forever