A jurisdiction imposes income tax using the following brackets.

Taxable income from $$0$ to $$10,500$ is taxed at $1\%.$

Taxable income from $$10,500$ to $$45,000$ is taxed at $15\%.$

Taxable income over $$45,000$ is taxed at $23\%.$

$($a$)(10$ points$)$ What is the tax on a taxable income of $$42,000?$ Make sure to indicate the contribution to the tax from each of the three brackets.

$($b$)(6$ points$)$ Find the effective tax rate on a taxable income of $$42,000.$