Carcass wrote:
The sum of a sequence of consecutive integers is 1,125 and the median is 45. What is the value of the greatest integer in the sequence?
A. 33
B. 45
C. 56
D. 57
E. 58
Kudos for the right answer and explanation
We are told that the median is
45In other words, when all of the consecutive numbers are arranged in ascending order,
45 is the middlemost number.
Now let's add a number on either side of
45 to get: 44,
45, 46
This is the same as writing: (45-1),
45, (45+1), and if we add these three values, the -1 and +1 cancel out to get: 45 + 45 + 45
The same applies to when we add TWO numbers on either side of
45We get: (45-2), (45-1),
45, (45+1), (45+2)
If we add these five values, the -1 and +1 cancel out, and the -2 and +2 cancel out to get : 45 + 45 + 45 + 45 + 45
1,125/45 = 25
So our sequence must consist of 25 values.
12 values must be greater than
4512 values must be less than
45And 1 value is equal to
45So our sequence looks like this: (45-12), (45-11), (45-10), ..... (45-2), (45-1),
45, (45+1), (45+2)...., (45+10), (45+11), (45+12)
What is the value of the greatest integer in the sequence? The greatest possible value = (45+12), which equals 57
Answer: D
Cheers,
Brent