F.2 Maths
2007-02-16 6:07 am
There are 375 students joining a Christmas party. Whan two-fifth of the boys are dancing with a girl each in the dance floor , 25 girls remain seated. How many girls are there in the Christmas party?
回答 (4)
2007-02-16 6:18 am
✔ 最佳答案
Suppose there are x boys in the party.that is (375-x) girls there.
2/5(x)+25 = 375-x (=no. of girls)
2x + 125 = 1875 - 5x
2x + 5x = 1875 -125
7x = 1750
x = 250
375 - 250 = 125
Ans.: There are 125 girls in the Christmas party.
參考: I am a maths teacher.
2007-02-16 6:23 am
Let x be the no of boys and y be the no of girls in the party
Boys dancing
=(2/5)x
=girl dancing with boys
Total no of people in the party
=375
=x+2x/5+25
x=250
Therefore total no of girls in the party
=y
=2x/5+25
=(2/5)*250+25
=125
Boys dancing
=(2/5)x
=girl dancing with boys
Total no of people in the party
=375
=x+2x/5+25
x=250
Therefore total no of girls in the party
=y
=2x/5+25
=(2/5)*250+25
=125
2007-02-16 6:22 am
Let y be the no. of boys
(2y/5 * 2) + 3y/5+ 25=375
7y/5=350
y=250
Hence the no. of girls is 375-250=125
唔知啱唔啱，有錯請指正
(2y/5 * 2) + 3y/5+ 25=375
7y/5=350
y=250
Hence the no. of girls is 375-250=125
唔知啱唔啱，有錯請指正
參考: me
2007-02-16 6:16 am
let the x be the number of girl
then, (375-x)*2/5=x-25
750-2x=5x-125
7x=875
x=125
so there are 125 girl in the party.
then, (375-x)*2/5=x-25
750-2x=5x-125
7x=875
x=125
so there are 125 girl in the party.
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