Answer: 
Step-by-step explanation:
Given
The surface area of a rectangular prism is 
Width of prism 
Length of prism 
height of prism 
Surface area is given by
![S.A.=2[lw+wh+hl]](https://tex.z-dn.net/?f=S.A.%3D2%5Blw%2Bwh%2Bhl%5D)
Put values
![34=2[2\times 1+1\times x+2x]\\17=2+3x\\15=3x\\x=5\ cm](https://tex.z-dn.net/?f=34%3D2%5B2%5Ctimes%201%2B1%5Ctimes%20x%2B2x%5D%5C%5C17%3D2%2B3x%5C%5C15%3D3x%5C%5Cx%3D5%5C%20cm)
Now, the volume of Prism is given by


So I think it would be $35 because if you multiply $3.50 by ten then it would be $35
The answer is 80, 2x+3x+4x=180, so x=20. 20*4=80.
This is a problem of Permutations. We have 3 cases depending on the number of B's. Since no more than three B's can be used we can use either one, two or three B's at a time.
Case 1: Five A's and One B
Total number of letters = 6
Total number of words possible = 
Case 2: Five A's and Two B's
Total number of letters = 7
Total number of words possible = 
Case 3: Five A's and Three B's
Total number of letters = 8
Total number of words possible = 
Total number of possible words will be the sum of all three cases.
Therefore, the total number of words that can be written using exactly five A's and no more than three B's (and no other letters) are 6 + 21 + 56 = 83