Bennett tried to solve exercise 1 a few different ways. Which of his methods are correct? Of the other methods, which makes the most sense to you? Explain

A. 5% sales tax means that for every dollar you spend, you need to pay a nickel in tax. If you buy a nickel tax. If you buy something for $21, you need to pay 21 nickels in tax.
B. You can set up a promotion and solve for the missing value.
$.05 = x <-- (These are fractions)
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$1.00 $21.00

C. If you know that 10% of $21 is $2.10, so 5% should be half of $2.10
D. 5% is equal to 1/20. To find the amount of tax on $21, find $21 ÷ 20
E. 1% of $21.00 is $0.21 so 5% of $21.00 is 5 x $ 0.2