Answer:
512
Step-by-step explanation:
Suppose we ask how many subsets of {1,2,3,4,5} add up to a number ≥8. The crucial idea is that we partition the set into two parts; these two parts are called complements of each other. Obviously, the sum of the two parts must add up to 15. Exactly one of those parts is therefore ≥8. There must be at least one such part, because of the pigeonhole principle (specifically, two 7's are sufficient only to add up to 14). And if one part has sum ≥8, the other part—its complement—must have sum ≤15−8=7
.
For instance, if I divide the set into parts {1,2,4}
and {3,5}, the first part adds up to 7, and its complement adds up to 8
.
Once one makes that observation, the rest of the proof is straightforward. There are 25=32
different subsets of this set (including itself and the empty set). For each one, either its sum, or its complement's sum (but not both), must be ≥8. Since exactly half of the subsets have sum ≥8, the number of such subsets is 32/2, or 16.
<span>√85</span>≈<span>9.21954445
Hope this helps. c:</span>
Answer:
Perimeter =63 inches
Area = 243in²
Step-by-step explanation:
Given data
Length of computer = 18in
Width of computer = 13.5in
From the given data the computer has a rectangular shape
Perimeter of the computer = L+L+W+W= 2L+2W
Perimeter = 2(18)+ 2(13.5)
Perimeter = 36+27=63 inches
Area of rectangular shape = L*W
Area = 18 x 13.5= 243in²
Answer:
use desmos :)) it helps
Step-by-step explanation:
Answer:
A
Step-by-step explanation:
v=πr2h
r=(3)²* 5
45π unit³
