Answer:
Step-by-step explanation:
In the context of this problem, ...
a) 25% of $50 = 25/100 × $50 = $12.50
b) 5% of $30 = 5/100 × $30 = $1.50
c) 10% of $45 = 10/100 × $45 = $4.50
d) 30% of $40 = 30/100 × $40 = $12.00
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Additional comment
Many calculators and all spreadsheets can work with percentages directly, without the need to convert them to a fraction or a decimal.