Set A is composed of nine numbers, labeled A1 through A9. Set B is als

C is not correct. Anyone else?

Yes, the correct answer is E.

Note that the Official Answer is E, not C.

I am a bit old fashioned and just wrote it all out on paper and used the plug-in method. At first I chose #s for A and then I used the rule that was given to figure out the values for B. Calculations are below. This took me 2min25sec.

A1=3 B1= 4
A2=4 B2 = 6
A3=5 B3=8
A4=6 B4=10
A5=7 B5=12
A6=8 B6=14
A7=9 B7=16
A8=10 B8=18
A9=11 B9=20
mean= sum/9 = 7 mean= sum/9 = 12
range= 11-3 = 8 range = 20-4 = 16
mean + range: 15 mean + range: 28

(set B mean + range) - (set A mean + range) = 28 - 15 = 13

Answer C!

Set A - A1, A2, A3, A4 and so on......

Set B: A1 +1, A2 +2, A3+ 3, A4+4 ,A+5...-> 1+2+3+4+5+6+7+8+9 = 45/9 =5 (mean of set B)
Range of set B from 1 to 9 = 8

Set A: B1-1, B2-2, B3-3, B4-4, B5-5....-> -1-2-3-4-5-6-7-8-9 = -45/9 = -5 ( mean of set A)
Range of set A from -1 to -9 = 8

5+8 = 13
-5+8= 4

Hence 13-4= 9

Answer B.

Does it make any sense or have I broken all math rules ? ☺
I am new here.
Thank You !

Answer C = 13.

A (A1+.....+A9)
B (B1+.....+B9) = (A1+.....+A9) + 45

A

Mean = (A1+....+A9)/9
Range = A9-A1

B

Mean = (A1+...+A9+45)/9 = (A1+....+A9)/9 + 5
Range = A9+9-(A1+1) = A9-A1+8

Combining

(A1+....+A9)/9 + 5+ A9-A1+8 - ((A1+....+A9)/9+A9-A1) = 5+8 = 13

Answer C - In my view

Tks! i saw my mistake, i assumed sets A and B as sequence, i can`t make this inference.

Case 1:
A = 0, 0, 0, 0, 0, 0, 0, 0, 0 --> range = 0, mean = 0, range + mean = 0
B = 1, 2, 3, 4, 5, 6, 7, 8, 9 --> range = 8, mean = 5, range + mean = 13
B's sum - A's sum = 13-0 = 13

Case 2:
A = 9, 8, 7, 6, 5, 4, 3, 2, 1 --> range = 8, mean = 5, range + mean = 13
B = 10, 10, 10, 10, 10, 10, 10, 10, 10 --> range = 0, mean = 10, range + mean = 10
B's sum - A's sum = 10-13 = -3

Since the two cases yield different results, the difference between B's sum and A's sum cannot be determined.



The use of the word larger in the question stem incorrectly implies that B's sum must be larger than A's sum.
To avoid this miscommunication, the question stem should simply ask for the difference between B's sum and A's sum.

Given:
1. Set A is composed of nine numbers, labeled A1 through A9.
2. Set B is also composed of nine numbers, labeled B1 through B9.
3. Set B is defined as follows: B1 = 1 + A1; B2 = 2 + A2; and so on, including B9 = 9 + A9.

Asked: How much larger is the sum of set B's mean and range than the sum of set A's mean and range?

A = {A1,A2, ,,, A9}
B = {B1,B2,,,,B9} = {1+A1,2+A2,,,,,9+A9}

Mean of B = \(\frac{A1+A2+.... + A9 + 45}{9} = \frac{A1+A2 +... + A9}{9} + 5\) = Mean of A + 5
Since we don't know minimum and maximum of numbers {A1,A2,,, A9}, Range can not be determined.

IMO E

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