T-shirts are $12. Calendars are $8. Students sold 40 items and raised $384. How many t-shirts and calendars did they sell

Question

How do you solve the problem? What kind of set up do you use?

Answer 1

Let T = # tee shirts sold

Let C = # calendars sold

 

eqn 1)  12T + 8C = 384     representing the money made

eqn 2)      T + C = 40        representing 40 items sold

 

in the 2nd equation solve for one variable in terms of the other

C = 40-T

 

in eqn 1 replace C with 40-T and solve for T

 

12T + 8(40-T) = 384

12T + 320 - 8T = 384

4T + 320 = 384

4T = 64

T = 16

 

They sold 16 tee shirts

 

Total items sold was 40 so 40-16 = 24 calendars sold