((5x5)/2)x2=50 square ft
(8x5)x2= 80 square ft
8x7= 56 square ft
50+80+56=186 square ft
D) 186 square ft
A geometric sequence is a sequence in which there is a common ratio between any two consecutive terms. In this case if X:Y:Z are in the ratio of 2:7:8 the multiplying by a constant k, we have X=2k, Y= 7k and Z=8k.
Then if X, Y-12, Z form a Geometric sequence, it means X/Y-12=Y-12/Z which is the same as 2k/7k-12=7k-12/8k if we cross multply, we get
16k²= 49k²-168k +144
33k²-168k+144 =0 solving for k
k = 4 or 1.091 if we take the whole number to find the values of X,Y and z,
X= 8, Y= 28 and Z=32
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1) Turn off Wifi
2) Go to hint and get the answer
3) Take picture of answer or remember it
4) Go to inspect element ——> arrows that look like this “>>”—> Application—-> Local Storage (click it until it says khan academy .com etc then click that then go to “X” by value and next to it click that then turn on wifi and put the answer
The expression in company B represents that is is in arithmetic progression where first term is 42000 and common difference is 1800 . So we have to use the formula of sum of n terms which is
Where a is the first term, n is the nth term, d is the common difference
On substituting there values,we will get
= 15(84000+52200) = 15*136200 =2043000
And for company A, it is
Difference between them =2043000-2002500= 40500
So the correct option is the second option .
