Total students = 28
Students with brown eyes = 19
students wear glasses = 13
Not brown eyes or no glasses = 7
Not brown eyes = 28 - 19 = 9
Not wearing glasses = 28 - 13 = 15
Not brown eyes and wearing glasses = 15 - 9 = 6
Brown eyes and wearing glasses = 13 - 6 = 7 <==== answer
Answer:
Please add a attachment.
Step-by-step explanation:
Let's call the width: w
the lenght is then 3w+4 ("4 more than 3 times the width")
and the parameter would be 2(w+3w+4), that is 2*(4w+4), that is 8w+8.
this is also equal to 18.4:
8w+8=18.4
8w=10.4
w=1.3
this is the width, and the lenght is:
4+3*1,3=4+3.9=7.9
and the area is their product:
1.3*7.9=10.27
The fourth one I think hope it helps