Question

Kersha has two jobs. During the day she works as an office clerk, and in the evening she works as a cashier. Her office job pays her $12.00 per hour. Her cashier job pays her $8.25 per hour. In one week, Kersha worked 55 hours. She earned a total of $585.
How many hours did Kersha work in each job?

a.) Office clerk: 35 hours; cashier: 20 hours

b.) Office clerk: 31 hours; cashier: 24 hours

c.) Office clerk: 20 hours; cashier: 35 hours

d.) Office clerk: 28 hours; cashier: 27 hours

Answer 1

Let x =  hours worked as a clerk ($12 per hour).
Let y = hours worked as a cashier ($8.25 per hour).

She worked 55 hours, therefore
x + y = 55             (1)

She earned $585, therefore
12x + 8.25y = 585        (2)

From (1), obtain
y = 55 - x           (3)

Substitute (3) into (2).
12x + 8.25(55 - x) = 585
12x + 453.75 - 8.25x = 585
3.75x = 131.25
x = 35
y = 55 - x = 55 - 35 = 20

Answer: a)  Office clerk: 35 hours; cashier: 20 hours.