As a follow up to this thread, I had the following question on my MGMAT CAT exam. I'd like some input from high scorers (Beny, this means you! 
) on whether they can do this question in 2 min.
This is not a hard question, but it takes me over 3 min to translate the problem and work through the math with enough care so that I don't make careless mistakes or misunderstand part of the question etc. So if I see a question like this, should I just make the best educated guess and move on? It is especially difficult for me to do that for these types of questions because I know it's just a matter of getting through the calculations without making a careless mistake.
The question is pasted below. I would appreciate any input on this.
At Jefferson Elementary School, the number of teachers and students (kindergarten through sixth grade) totals 510. The ratio of students to teachers is 16 to 1. Kindergarten students make up 1/5 of the student population and fifth and sixth graders account for 1/3 of the remainder. Students in first and second grades account for 1/4 of all the students. If there are an equal number of students in the third and fourth grades, then the number of students in third grade is how many greater or fewer than the number of students in kindergarten?
12 greater
17 fewer
28 fewer
36 fewer
44 fewer
) on whether they can do this question in 2 min.This is not a hard question, but it takes me over 3 min to translate the problem and work through the math with enough care so that I don't make careless mistakes or misunderstand part of the question etc. So if I see a question like this, should I just make the best educated guess and move on? It is especially difficult for me to do that for these types of questions because I know it's just a matter of getting through the calculations without making a careless mistake.
The question is pasted below. I would appreciate any input on this.
At Jefferson Elementary School, the number of teachers and students (kindergarten through sixth grade) totals 510. The ratio of students to teachers is 16 to 1. Kindergarten students make up 1/5 of the student population and fifth and sixth graders account for 1/3 of the remainder. Students in first and second grades account for 1/4 of all the students. If there are an equal number of students in the third and fourth grades, then the number of students in third grade is how many greater or fewer than the number of students in kindergarten?
12 greater
17 fewer
28 fewer
36 fewer
44 fewer
