Hi Rishab2409,Yes, your reasoning is spot on, and your answer of
130 is correct. Let me just confirm the
why behind each of the two bounds so it's airtight.
Maximum range = 250. The question caps every score in the window
500 to
750. So the widest the combined
15 scores can ever spread is
750 - 500 = 250 - and that's reachable: let one person hit
750 and another hit
500, and their individual ranges (
80 and
120) still fit comfortably inside. So the ceiling of
250 is real, not just theoretical.
Minimum range = 120. This is the part worth stating cleanly. When you pool everyone's scores together, the whole group
includes the person whose scores already span
120. You can never make the combined spread smaller than a spread that's already sitting inside the group. So the combined range is forced to be
at least 120 - the largest single individual range. And
120 is achievable: stack everyone inside one
120-wide window (e.g. all scores in
500-
620), and the two smaller-range people tuck inside the biggest one.
So
250 - 120 = 130. Your logic matches exactly.
One quick way to lock in the min idea: suppose a subgroup of numbers already ranges from
500 to
620. Can adding
more numbers to that group ever make its overall range
smaller than
120? No - the
500 and the
620 are still in there. Adding points can only keep the range the same or push it wider, never shrink it. That's the whole reason the minimum can't dip below the biggest individual range.
Answer: ERishab2409
Please correct my understanding - I saw the maximum range is 250 (750-500 as given in question) and the minimum range will always be the highest range of the three individuals which is 120, and then the difference (130) would be the answer.