Question 137385
Let x=number of boys and girls in the class on the first day of school

Then 0.6x=number of boys
and 0.4x=number of girls
After the shuffle, we have:
Number of boys=0.6x+6
Number of girls=0.4x-6

Now we are told that the following situations exist after the shuffle:
0.75x=0.6x+6 (boys) subtract 0.6x from each side
0.15x=6  divide both sides by0.15

x=40-----------------------number of boys and girls in the class on the first day of school


We can also arrive at the answer with the following equation (girls):

0.25x=0.4x-6  subtract 0.4x from each side
-0.15x=-6 or
x=40

CK
first day of school:
0.6*40=24 boys
0.4*40=16 girls
24+16=40
40=40
after the shuffle:

0.75(40)=24+6
30=30
0.25(40)=16-6
10=10


Hope this helps---ptaylor