There are 300 seniors at Morse High School, and 50% of them have cars. Of the remaining grades (freshmen, sophomores, and juniors), only 10% of them have cars. If 18% of all the students at Morse have cars, how many students are in the three lower grades?	Choose the correct choice from the following choices:  A) 600  B) 900  C) 1200  D) 1350  E) 1500
Let x be the number of students in the lower three grades.   0.1x + 150 = 0.18(x+300)   0.08x = 96   x = 1200   The answer is 1200.
<result>C</result>
There are 300 seniors at Morse High School, and 50% of them have cars. Of the remaining grades (freshmen, sophomores, and juniors), only 10% of them have cars. If 18% of all the students at Morse have cars, how many students are in the three lower grades?