Question

. Three types of shirts sold at a store cost $9.00, $11.00, and $12.50. One day, the store sells a total of 23 shirts and makes $243 on the sales. Twice as many shirts were sold for $12.50 than were sold for $11.00. If x represents $9.00 shirts, y represents $11.00 shirts and z represents $12.50 shirts, how many of each type of shirt were sold?

Write a system of equations to represent this situation and then solve the system.


There are 2 parts to this question.


#1 - Write the system of 3 equations.


#2 - write the solutions to the system.

Answer 1

X + 3y = 23

9x + 36y = 243

11 shirts sold at $9.0 per shirt, 4 shirts sold at $11 per shirt and 8 shirts sold at $12.5 per shirt

Explanation:

-----Since we are told to assume that the number of shirts sold for $9.00 each is x, that of $11.00 is y and also that of $12.50 is z.

9x + 11y + 12.5z = 243

9x + 11y + 12.5(2y) = 243

9x + 36y = 243_______ equation 1

----- The statement also read that One day, the store sells a total of 23 shirts and makes $243 on the sales. TWICE AS MANY SHIRTS WERE SOLD FOR $12.50 THAN WERE SOLD FOR $11.00

Z = 2y

x + y + z = 23

X + y + 2y = 23

X + 3y = 23_____ equation 2

Now multiply the above by 9 to have this equation's "x" sharing the same coefficient with that of equation 1

9x + 27 = 207 will be the new one___equation 3

-----Subtract equation 3 from 1 and we have

9x + 36y = 243____ equation 1

9x + 27y = 207____ equation 3

9y = 36

Y = 4

-----Substitute y = 4 in equation 2

X + 3y = 23

X + 4(3) = 23

X + 12 = 23

X = 23 - 12

X = 11

-----Remember that x + y + z = 23

11 + 4 + z = 23

15 + z = 23

Z = 23 - 15

Z = 8.

So therefore, x =11 shirts, y = 4 shirts and z = 8 shirts