Step 1: Use the mean
Arithmetic mean = 48 for 5 integers.
So total sum is:
5×48=240
We are also told:
E=100
Therefore:
A+B+C+D=140
Now we must find:
Greatest possible value of C
Least possible value of C
Then subtract.
PART 1: Greatest possible value of C
To maximize the median C:
We want the other numbers as small as possible so more “sum budget” remains for C.
Since all are positive integers and strictly increasing:
Smallest possible:
A=1,B=2
Now since:
C<D<100
To maximize C, make D as small as possible:
D=C+1
Now use the sum:
1+2+C+(C+1)=140
2C+4=140
2C=136
C=68
So greatest possible median:
68
PART 2: Least possible value of C
Now we minimize C.
To do that, make D as large as possible while keeping:
D<100
Largest possible:
D=99
Now A,B must still be distinct positive integers less than C.
To minimize C, make them as close as possible to C:
A=C−2,B=C−1
Now use the sum:
(C−2)+(C−1)+C+99=140
3C+96=140
3C=44
C=
3
44
But C must be an integer.
Closest integer satisfying constraints:
C=15
Check:
A=13, B=14, C=15, D=98, E=100
Sum:
13+14+15+98+100=240
Works.
So least possible median:
15
Step 3: Difference
68−15=53
Final Answer
C. 53