Answer:
5% sales-tax rate was she charged for this blazer
Explanation:
As per the statement:
Jan bought a blazer for $39.90.
The price of the blazer was $38.
Sales tax price = 39.90 - 38 = $1.90
We have to find the sales-tax rate was she charged for this blazer percentage wise.
Using formula:

Substitute the given value we have;

Therefore, 5% sales-tax rate was she charged for this blazer percentage wise