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King Group Title

: Help..............In a school a certain number of boys and girls attend a certain examination. The mean mark of the boys was 40 and the mean mark of the girls was 60.Mean of all students is 48.Find the number of boys and girls in a class of 100.

  • 3 years ago
  • 3 years ago

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  1. wasiqss Group Title
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    (40x+60y)/100=48 x+y=100

    • 3 years ago
  2. wasiqss Group Title
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    solve two simoultaneous eq

    • 3 years ago
  3. wasiqss Group Title
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    boys r 60, galx 100

    • 3 years ago
  4. King Group Title
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    not possible sorry wrong answer x+y needs to be 100

    • 3 years ago
  5. wasiqss Group Title
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    sorry i mean to say galx 40

    • 3 years ago
  6. wasiqss Group Title
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    typed wrong

    • 3 years ago
  7. King Group Title
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    oh ok but how did u get first two equations....xplain

    • 3 years ago
  8. King Group Title
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    sry only first equation

    • 3 years ago
  9. wasiqss Group Title
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    listen what will be mean of marks? total marks divided by candidate

    • 3 years ago
  10. King Group Title
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    and what is x and what is y?

    • 3 years ago
  11. wasiqss Group Title
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    x is boys , y is number of galx

    • 3 years ago
  12. King Group Title
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    yeah but how 40 * x and 60 * y?

    • 3 years ago
  13. wasiqss Group Title
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    so the total marks is number of boys into their marks+number of galx nto their mean marks then divided by total number of students that s 100

    • 3 years ago
  14. wasiqss Group Title
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    ok

    • 3 years ago
  15. King Group Title
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    why is 40 multiplied by x and 60 multiplied into y?

    • 3 years ago
  16. wasiqss Group Title
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    40 is the mean marks of boys and x is the total number of boys in class and y is total number of gals ad 60 is the mean marks of gal

    • 3 years ago
  17. King Group Title
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    yeah so why do we multiply?

    • 3 years ago
  18. King Group Title
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    why do we multiply?

    • 3 years ago
  19. King Group Title
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    why do we multiply?

    • 3 years ago
  20. King Group Title
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    anwar help?

    • 3 years ago
  21. AnwarA Group Title
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    OK. Let \(n\) and \(m\) be the number if boys and girls respectively, then \(40 n\) is the total points that boys scored, and \(60m\) is the total of the girls. We can then write \(\frac{40n+60m}{m+n}=48\). We also have \(m+n=100\). Solve them to find m and n.

    • 3 years ago
  22. wasiqss Group Title
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    we multiply to get the total number of marks like suppose there are 3 students in class and their mean mark is 90 so how we will get the marks obtained by class in total as in we want to add the marks of all the student

    • 3 years ago
  23. AnwarA Group Title
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    If you solve them, you will get \(n=70 \text{ boys, and } m=30 \text{ girls}\).

    • 3 years ago
  24. King Group Title
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    no anwar u are wrong

    • 3 years ago
  25. King Group Title
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    wasiq why will we multiply if 3 students are there then mmean is x1+x2+x3/3=90

    • 3 years ago
  26. AnwarA Group Title
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    Oh sorry, I solved them for \(46\), not \(48\). Wait a sec.

    • 3 years ago
  27. AnwarA Group Title
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    60 boys and 40 girls :)

    • 3 years ago
  28. King Group Title
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    yea anwser is rite but i dont understand why we multiply...

    • 3 years ago
  29. asnaseer Group Title
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    the mean of the these 3 numbers: 12,14,16 is calculated as:\[\frac{12+14+16}{3}=\frac{42}{3}=14\]the total of those 3 numbers is: 12+14+16=42, which is the same as the mean times the number of numbers you have: 14*3=42

    • 3 years ago
  30. wasiqss Group Title
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    king u r dumb, sorry to say bt tru

    • 3 years ago
  31. asnaseer Group Title
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    so, if you are given the mean and the number of items, you can always work out the total number of items as (mean)*(number of items)

    • 3 years ago
  32. AnwarA Group Title
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    Let me explain it to you. Assume we have 5 students, and their mean is 50. We can write that as \(\large{\frac{x_1+x_2+x_3+x_4+x_5}{5}=50}\). Now if we want to find the sum of the points that all the 5 student scored, we just multiply both sides by \(5\) to get \(\large {x_1+x_2+x_3+x_4+x_5=5\times 50}\). Makes sense?

    • 3 years ago
  33. asnaseer Group Title
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    sorry "the total of all the items"

    • 3 years ago
  34. King Group Title
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    oh ok thnx anwar and asnaseer thnk u very much

    • 3 years ago
  35. asnaseer Group Title
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    no problem - always glad to help

    • 3 years ago
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