There are 12 boys and 10 girls in your gym class. if 6 boys joined the class, how many girls would need to join for the ratio of boys to girls to remain the same?

Since the ratio is 12:10 and 6 boys are added then there will be 18 boy and 5 more girls will have to be added. The ratio will then be 18:15. Explanation: 6 is the unit rate for the boys because 6 times 2 equals 12 and 6 times 3 equals 18. You use the same thing for the girls, the unit rate for the girls is 5 because 5 times 2 is 10 and 5 times 3 is 15. Hope I helped