The value of a car declined 20% per year. what percent of the original value remains after 2 years

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Which of the following is correct interpretation of the expression -4+13

Ariel is working at a meat packing plant for 5 nights a week. her regular wage is $11 an hour. she earns tine and a half for any overtime hours. this week she worked 9 hours of over time .how much will ariel earn for overtime this week ?