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April 18, 2014

April 18, 2014

Posted by **srihita** on Monday, March 26, 2012 at 10:23am.

1) How many boys were in the hall at first?

2)Ho many more boys than girls were in hte hall at first?

- maths -
**A.P.**, Monday, March 26, 2012 at 10:55amYou can set the number of boys to be x and the number of girls to be y.

After a third of the boys leave, you are left with 2/3x. 22 new girls arrive, so you get y+22

Now, you have a system of equations:

x+y = 256

2x/3 = y+22

Express y in terms of x in second equation:

y= 2x/3 -22

Set 2x/3 -22 into the first equation in stead of y.

(2x/3)-22+x = 258

5x/3 = 280

x=168

That means that y = 258-168 = 90

Controll: 90+22=112; 168*2/3=112;

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