Number of Possible Sums with 1-15 Cards

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SUMMARY

The discussion centers on calculating the number of distinct sums possible using a set of 15 cards, consisting of 8 cards with the number 10, 5 cards with the number 100, and 2 cards with the number 500. The initial claim states that 143 distinct sums can be formed, but one participant argues that at least two cards are needed for a valid sum, leading to a calculation of 141 distinct sums. The discrepancy arises from the interpretation of the problem's conditions, specifically the inclusion of sums formed with one card.

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  • Understanding of combinatorial mathematics, specifically binomial coefficients.
  • Familiarity with distinct sum calculations in combinatorial contexts.
  • Knowledge of basic card counting principles and their application in probability.
  • Ability to apply formulas for combinations, such as $\binom{n}{k}$.
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  • Research the application of the formula $\binom{r+n-1}{r-n+1}$ for calculating distinct sums in combinatorial problems.
  • Explore the concept of generating functions to understand how to compute distinct sums more efficiently.
  • Study examples of distinct sum problems involving multiple sets of items to gain deeper insights.
  • Learn about the principles of combinatorial optimization to enhance problem-solving skills in similar scenarios.
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WMDhamnekar
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There are 8 cards with number 10 on them, 5 cards with number 100 on them and 2 cards with number 500 on them. How many distinct sums are possible using from 1 to all of the 15 cards?Answer given is 143. But my logic is for any sum, at least 2 numbers are needed. So, there are $\binom{15} {2} + \binom{15}{3}+...\binom{15}{15} $ distinct sums. So, I think answer 143 is wrong.
What is your opinion?
 
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\begin{pmatrix}15 \\ 2 \end{pmatrix} is the number of sums of two of the numbers, \begin{pmatrix}15 \\ 3 \end{pmatrix} is the number of sums of three of the numbers, etc. But they won't be distinct sums.
 
Dhamnekar Winod said:
There are 8 cards with number 10 on them, 5 cards with number 100 on them and 2 cards with number 500 on them. How many distinct sums are possible using from 1 to all of the 15 cards?Answer given is 143. But my logic is for any sum, at least 2 numbers are needed. So, there are $\binom{15} {2} + \binom{15}{3}+...\binom{15}{15} $ distinct sums. So, I think answer 143 is wrong.
What is your opinion?

The directions clearly state from 1 to 15, so their solution is based on that premise.
 
CountryBoy said:
\begin{pmatrix}15 \\ 2 \end{pmatrix} is the number of sums of two of the numbers, \begin{pmatrix}15 \\ 3 \end{pmatrix} is the number of sums of three of the numbers, etc. But they won't be distinct sums.

Hello,

I have computed 141 distinct sums. But the answer is 143. Which 2 distinct sums i omitted, would you tell me? Is the answer 143 wrong? All the 141 distinct sums are

20,30,40,50,60,70,80,110,120,130,140,150,160,170,180,200,210,220,230,240,250,260,270,280,300,310,320,330,340,350,360,370,380,400,410,420,430,440,450,460,470,480,500,510,520,530,540,550,560,570,580,600,610,620,630,640,650,660,670,680,700,710,720,730,740,750,760,770,780,800,810,820,830,840,850,860,870,880,900,910,920,930,940,950,960,970,980,1000,1010,1020,1030,1040,1050,1060,1070,1080,1100,1110,1120,1130,1140,1150,1160,1170,1180,1200,1210,1220,1230,1240,1250,1260,1270,1280,1300,1310,1320,1330,1340,1350,1360,1370,1380,1400,1410,1420,1430,1440,1450,1460,1470,1480,1500,1510,1520,1530,1540,1550,1560,1570,1580.


I know one formula $\binom{r+n-1}{r-n+1}$ which computes distinct sums, where n=cells and r= balls. How to use that here? Or is there any other formula?
 
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