if there 8 boys for every 7 girls with 195 total, how many are boys?


Sagot :

b = boys   g = girls
.................................

b + g = 195        b = 195 - g

b = 8
g    7

Substitute b for 195 - g in the 2nd equation:

b = 8
g    7

195 - g = 8
    g        7

Cross Multiply

8g = 7 . ( 195 - g )
8g = 1365 - 7g
8g + 7g = 1365
15g = 1365
g = 1365
        15
g = 91

Substitute g for 91 in one of the equations:

b + g = 195
b + 91 = 195
b = 195 - 91
b = 104


S = 104 boys.