SOLUTION: if three positive integers are added two at a time, the sums are 998, 1050, and 1234. the difference between the largest and the smallest number is: A) 224 B) 236 C) 248 D) 250

Algebra ->  Finance -> SOLUTION: if three positive integers are added two at a time, the sums are 998, 1050, and 1234. the difference between the largest and the smallest number is: A) 224 B) 236 C) 248 D) 250      Log On


   



Question 1123470: if three positive integers are added two at a time, the sums are 998, 1050, and 1234. the difference between the largest and the smallest number is:
A) 224
B) 236
C) 248
D) 250
E) 262

Found 2 solutions by ikleyn, MathLover1:
Answer by ikleyn(52896) About Me  (Show Source):
You can put this solution on YOUR website!
.
Then the difference between the largest and smallest is 1234 - 998 = 236.


Solution

     998 = the sum of the smallest and the middle numbers;


    1234 = the sum of the middle and the greatest number.


    When you take the difference, the middle terms will cancel each other, and you will get what the question is asking for.

Solved.

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The lesson to learn from this solution is THIS :

    You do not need to find each number individually to get the answer.



Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!

let’s three positive integers be x,y, and z
if added two at a time, we have sums as

x%2By, x%2Bz, and y%2Bz
if the sums are 998, 1050, and 1234, we have
x%2By=998........eq.1
x%2Bz=1050........eq.2
y%2Bz=1234........eq.3
--------------------------------------------solve this system
x%2By=998........eq.1....solve for x
x=998-y........eq.a
x%2Bz=1050........eq.2....solve for x
x=1050-z.........eq.b
from eq.a and eq.b we have:
998-y=1050-z ....solve for y
998-1050%2Bz=y
y=z+-52.................eq.c
substitute y in y%2Bz=1234........eq.3
z-52%2Bz=1234
2z=1234%2B52
2z=1286
z=1286%2F2
highlight%28z=643%29
now find y
y=z+-52.................eq.c
y=643+-52
highlight%28y=591%29
and, find x
x=998-y........eq.a
x=998-591
highlight%28x=407%29

so your numbers are:
highlight%28643%29->the largest
highlight%28591%29
highlight%28407%29->the smallest
and, the difference between the largest and the smallest number is:
highlight%28643-407=236%29
so, your answer is: B) 236