Question

Percy works two part-time jobs to help pay for college classes. On Monday, he works 3 hours at the library and 2 hours at the coffee cart and earns $36.50. On Tuesday, he works 2 hours at the library and 5 hours at the coffee cart and earns $50. His hourly wage at the library, x, and hourly wage at the coffee cart, y, can be determined using the system of equations below.
3x + 2y = 36.50
2x + 5y = 50.00
At which job does Percy earn the greater hourly wage? How much does Percy earn each hour at this job?

A.Percy earns a greater hourly wage of $7.00 at the library.
B.Percy earns a greater hourly wage of $7.00 at the coffee cart.
C.Percy earns a greater hourly wage of $7.50 at the library.
D.Percy earns a greater hourly wage of $7.50 at the coffee cart.

Answer 1

We need to solve this system 
(3x + 2y = 36.50)    *5
(2x + 5y = 50.00)    *(-2)

  15x+10y= 182.5
   -4x  -10y= -100

11x=82.5
x= 7.50  at the library


2x + 5y = 50.00   
2*7.5+5y=50
15+5y=50
5y=35
y=7 at coffee cart

So,
correct answer is 
C.Percy earns a greater hourly wage of $7.50 at the library.