The ratio of boys to girls miss Thompson's class is 2 to 3 there are 18 girls in the class what is the total number of students in Miss Thompson's class

Multiple choice or not?

So the first thing we do is to multiply the top equation by 3. the reason i want to do this is i notice there will be a 6y on both equations and can possibly add/subtract them. so we get 6y = -3x + 27. adding that and the second equation we get 6x = 27-15 which is 12. divide by 6 and we get 2. ∴ x = 2. substituting 2 into the first equation we get 2y = -2 + 9 which is 7. divide by 2 and we get 7/2. ∴ y = 7/2, x = 2.

The answer is 90 % because since 20 multiplied by 5 is 100 you would have to do each question multiplied by 5 so 18 times 5 equals ninety percent.