Answer:
The length of XY is either 10 or 2.5.
Step-by-step explanation:
Given information: ZY = 5, XC = 3 and DC = 4.
Case 1: Rectangle ABCD is smaller than ZBXY.
The opposite sides of the rectangle are same.



The length of ABCD is 4 and width of ABCD is 2. The width of ZBXY is 5. The corresponding sides of the similar rectangles are is in the same proportion.



Therefore the value of XY is 10.
Case 2: Rectangle ABCD is larger than ZBXY.



The length of ABCD is 4 and width of ABCD is 8. The width of ZBXY is 5. The corresponding sides of the similar rectangles are is in the same proportion.



Therefore the value of XY is 2.5.
Most of the information's necessary for solving this problem is already given in the question.
Let us assume the number to be = x
Then
25% * x = 19
(25/100) * x = 19
x/4 = 19
x = 19 * 4
= 76
So the unknown number is 76. I hope there is no complexity in the method described above and also the procedure is clear enough for you to understand. You can use this method for solving similar type of problems in future without requiring any additional help from outside.
10=2x+3,50 |-3,50
6,50=2x |:2
3,25=x
10=2x+7 |-7
3=2x |:2
1,5=x
You didnt say how many bakery she wants to buy, so i did one inequality for 1 bakery anderen for the maximum of 2.
Try out this website or search "surface area of a triangular prism" in Google
http://www.ck12.org/geometry/Surface-Area-of-Triangular-Prisms/lesson/Surface-Area-of-Triangular-Pri...