A group of boys and girls are at a school dance. Fifteen girls leave the dance and then there are two boys at?

Question

the dance for every girl. Later, 45 boys leave the dance and then there are five girls for each boy remaining at the dance. How many girls were at the dance at the beginning?

Please show your work! Thanks!

Answer 1

Let

b = number of boys originally at dance
g = number of girls originally at dance

Then

2(g - 15) = b
5(b - 45) = g - 15

2g - 30 = b
5b - 225 = g - 15

Substituting for b

5b - 225 = g - 15
5(2g - 30) - 225 = g - 15
10g - 150 - 225 = g - 15
9g = 360
g = 40

The number of girls originally at the dance was 40.

Answer 2

Let there were G no girls and B no. of boys at the beginning.
15 girls leave, that makes the no of girls (G-15). Now there are 2 boys for every girl. So,
B = 2(G-15) = 2G-30.............(1)
After 45 boys leave, the no. of boys is (B-45).
Now there are 5 girls for each boy.
So (B-45)x5 = G-15
or 5B-225 = G-15
or 5B = G+ 210
or 5(2G-30) = G + 210 [From (1)]
or 10G - 150 = G + 210
or 10G-G = 210 + 150
or 9G = 360
or G = 40. So no of girls at the beginning was 40.
Therfore No. pf boys at the beginning
= 2G-30 = 2x40 - 30 = 80 - 30 = 50.

Answer 3

Let no of girls=G
Let no of boys=B

Fifteen girls leave the dance ,thus no of girls=G-15
then there are two boys at the dance for every girl
thus.......2(G-15)=B..............(1)

Later, 45 boys leave the dance ,thus no of boys=B-45
then there are five girls for each boy remaining at the dance
thus.........5(B-45)=G-15...........(2)

Putting B=2(G-15) from (1) in (2)........
5[2(G-15)-45]=G-15
=>5[2G-30-45]=G-15
=>5[2G-75]=G-15
=>10G-375=G-15
=>9G=360
=>G=40
Thus number of girls at the dance floor in the beginning=40.......answer.......;-)

Answer 4

G-15 = 2B
5(B-45) = G-15

Answer 5

luv to be boy left with 5 to 1,to hard right now just thinking bout this,lol

Answer 6

Do your own homework, get smarter.

Answer 7

I dunno but those boys sure need some new cologne.