First, we're going to add the two ratios. This is our equation: 8+7=15. We now divide 195 (total campers) by 15, to make individual copies of our ratio. 195/15=13. We can fit our ratio, 8:7, into 195 13 times. We now multiply both numbers by 13 for the exact number of campers. 8x13=104, and 7x13=91. We can check our math by adding the two final numbers. 104+91=195. Since our number matches the total number of campers, we know it is correct. There are 104 boy campers and 91 girls.