Question 335395
x + y = 1200
y = 1200 - x
x= 1200 - y 

.1x + .5y = 480
.1x + .5(1200 - x) = 480 
.1x + 600 - .5x = 480
-.4x + 600 = 480
-.4x = -120 
x = 300 
therefore.. 10% of women on the north campus equal 300 students.. 
to find the whole amount divides.. 300/.1 = 3000 students on the north campus before the divide

.1x + .5y = 480
.1(1200 - y) + .5y = 480
120 - .1y + .5y = 480
120 + .4y = 480
.4y = 360 
y = 900
therefore 50% of students before the merge that were women was 900 students.. to find the whole amount of students on the east side divide.. 900/.5 = 1800 students on the north side before the merge.