Successive discounts of 2%

To find the single equivalent discount of successive discounts, we use:

Single discount
$ = a + b - \frac{ab}{100} $

where $a = 2%$ and $b = 21%$.

Step 1: Substitute values

$ = 2 + 21 - \frac{2 \times 21}{100} $

Step 2: Simplify

$ = 23 - \frac{42}{100} $

$ = 23 - 0.42 $

$ = 22.58% $

Answer: 22.58%