The sum of these positive integers is 505
The volume of the larger cube is 3*3*3, which is 27.
The volume of the smaller cubes is 1*1*1, which is 1.
27/1=27
That means all cubes will be used, so only the placement of the cubes matter.
The center of the cube will show no sides,
The center of the face will show 1 side, which has a surface area of 1sq.in.
Since there are 6 white cubes and 6 faces with 6 face centers, and only one cube center, there will be 5 cubes on the center of the faces and 1 in the cube center.
This means there will be 0 faces of 1 cube and 1 faces shown for the rest of the cubes. Since each face is 1sq.un., the rest is math
(0*1)+((1*1)5)
(0)+(1*5)
0+5
5sq.un. of the cube is white.
a=The fraction of surface area showing
b=Surface area of large cube
b=3*3*number of sides on cube(6)
5*a=b
5*a=54
a=54/5
Your answer is 54/5.
The cost of one ticket will be £8.20
<em><u>Explanation</u></em>
Suppose, the cost of one ticket is 
As the offer says "buy 3 tickets and get a ticket free" , it means <u>they actually need to pay for 3 tickets</u>.
So, the total cost of 3 tickets 
Each of four friends pay £6.15 , so the <u>total amount they pay</u> 
Thus, the equation will be .....

So, the cost of one ticket will be £8.20
The answer should be 2x-2