Answer:
Number of chicken sandwiches = 150
Number of turkey sandwiches = 150
Number of roast beef sandwiches= 100
Step-by-step explanation:
We are told the school cafeteriat makes and sells 3 different types of sandwiches which are; chicken, turkey and roast beef.
Let chicken be x, turkey be y and roast beef be z.
We are told they make 400 sandwiches in total.
Thus;
x + y + z = 400
However, we are told that the cafeteria makes same number of chicken and turkey sandwiches.
Thus, x = y
Thus;
Total is now;
x + x + z = 400
2x + z = 400 - - - (eq 1)
Now,we are told that chicken, turkey and roast beef sandwiches are sold for $3, $3.5 and $4 respectively. Also that the total amount realized from sales is $1375.
Thus;
3x + 3.5y + 4z = 1375
Since x = y. Thus;
3x + 3.5x + 4z = 1375
6.5x + 4z = 1375 - - - (eq 2)
Let's make z the subject in eq 1.
Thus;
z = 400 - 2x - - - (eq 3)
Putting 400 - 2x for z in eq(2) gives us;
6.5x + 4(400 - 2x) = 1375
6.5x + 1600 - 8x = 1375
1600 - 1375 = 8x - 6.5x
225 = 1.5x
x = 225/1.5
x = 150
Putting 150 for x in eq 3 gives;
z = 400 - 2(150)
z = 400 - 300
z = 100
Since x = y. Then y = 150
