We first need to find the difference between $70 and $49.
$70 - $49 = 21
Now we find out what percent $21 is of $70.
21/70 × 100 = 30%.
That means the discount is 30%!
Now we must find 30% of $100, which is $30.
Then we subtract $30 from $100.
$100 - $30 = 70$