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At a school
number of boys:number of girls =11:9
there are 124 more boys than girls
work out the total number of students at the school
(edited 6 years ago)

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Original post by lolu123
At a school
number of boys:number of girls =11:9
there are 124 boys then girls
work out the total number of students

u sure this isn't uni level maths - too difficult
Reply 2
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lolu123
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its on mathswatch
Reply 3
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ada_786
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Whate grade
Reply 4
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ada_786
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what*
Reply 5
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Notnek
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Original post by lolu123
At a school
number of boys:number of girls =11:9
there are 124 boys then girls
work out the total number of students

Please read through this question and check you've typed it correctly.
Reply 6
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lolu123
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Original post by Notnek
Please read through this question and check you've typed it correctly.


i meant to stay number of students at the school
Original post by lolu123
At a school
number of boys:number of girls =11:9
there are 124 boys then girls
work out the total number of students

I am not from UK but this is really basic, don't you learn the rule of three ( not sure if this is the proper translation ) ?
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Notnek
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Original post by lolu123
i meant to stay number of students at the school

there are 124 boys then girls

This doesn't make sense. Please edit your post to correct it.
Reply 9
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lolu123
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Original post by Notnek
there are 124 boys then girls

This doesn't make sense. Please edit your post to correct it.


i have now
Reply 10
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lolu123
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Original post by AndreiMiron
I am not from UK but this is really basic, don't you learn the rule of three ( not sure if this is the proper translation ) ?


work it out then
Original post by lolu123
work it out then


ok so you have b-boys g-girls t-students
you know g+124=b g=b-124 t=g+b
you have
11 boys ...... 9girls
b boys ...... g girls
then simply apply the rule
(edited 6 years ago)
Reply 12
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Notnek
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Original post by lolu123
At a school
number of boys:number of girls =11:9
there are 124 more boys than girls
work out the total number of students at the school

The easiest way to do this is to realise that 11-9 = 2 so two "parts" of the ratio represent how many more boys there are than girls.

So 2 parts = 124.
Then 1 part = 62

etc.

Does this help?
Reply 13
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lolu123
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Original post by Notnek
The easiest way to do this is to realise that 11-9 = 2 so two "parts" of the ratio represent how many more boys there are than girls.

So 2 parts = 124.
Then 1 part = 62

etc.

Does this help?


no
Original post by lolu123
no


If 1 part = 62 students
Then the total 20 parts = 62*20 = 1240 students <-- Total number of students in the school.
What the question's ratio tells us is that there for every 20 students (it's an 11:9 ratio so there's 20 parts to it) that 11 are boys and 9 are girls. In the school as a whole, there are 124 more boys than girls. That means that this extra difference of 2 parts (11 boys - 9 girls means 2 more boys per 20) refers to 124 boys. That means that if 2 parts extra boys is 124 (can be written as 2x = 124) then 1 part extra boys is just half of that (simple algebra, x = 124/2 = 62). Then since you know the school has 20 parts, you multiply the singular part, which we referred to as x, by 20 (20x = 1240) to get the total number of students for every part which is the total number of students.
11 boys to every 9 girls.
124 more boys then girls:
Boys(11/20) = 124 + Girls(9/20)
Therefore 11/20 - 9/20 = 124
This leads to 2/20 = 124 therefore 1/20 = 62

Girls = 9/20 = 62 x 9 = 558 Girls.
Boys = 11/20 = 62 x 11 =682 Boys
Therefore total students = 558 + 682 = 1240
Hope this helps :smile:
Original post by lolu123
At a school
number of boys:number of girls =11:9
there are 124 more boys than girls
work out the total number of students at the school


the ratio is 11:9 that's a difference of 2 and there are 124 more girls than boys so 124/2 = 62

62x11 =682 and 62*9 = 558

682 + 558 = 1240
Reply 18
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lolu123
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Original post by Zalvager
11 boys to every 9 girls.
124 more boys then girls:
Boys(11/20) = 124 + Girls(9/20)
Therefore 11/20 - 9/20 = 124
This leads to 2/20 = 124 therefore 1/20 = 62

Girls = 9/20 = 62 x 9 = 558 Girls.
Boys = 11/20 = 62 x 11 =682 Boys
Therefore total students = 558 + 682 = 1240
Hope this helps :smile:


thanks:colondollar:
Reply 19
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KLOIDA
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I know I'm late but just incase, you take away 9 from 11 = 11-9 = 2. 2 parts = 124. to find one part you just divide by 2 = 124 / 2 = 62. 62 x 11 = 682. 62 x 9 = 558. 682 +. 558 = 1240 (the answer). to check you can just do 682 - 558 which is 124
(edited 6 years ago)

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