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

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.