Answer:
$44.94
Step-by-step explanation:
400+100+100 = 600
22.40 + 10 +10 = 42.40
(22.40 for the first 400 and 10 for each additional 100)
If tax is 6%, you can multiply the whole thing (42.40) by 1.06 to get the total amount of 44.94.
Why 1.06? If you think about it, tax is 6%. 6% is the same as 0.06. You pay 100% for the products, so with tax, it's the equivalent of 106%, or 1.06.
