The present ratio of students to teachers at a certain school is 30 to 1. If the student enrollment were to increase by 50 students and the number of teachers were to increase by 5, the ratio of students to teachers would then be 25 to 1. What is the present number of teachers?
Select the correct option:
A) 5 B) 8 C) 10 D) 12 E) 15
Lets say T = 10 ---&gt; S = 300 ---&gt; 350/15 = a bit less than 25 (A and B will only make this ratio lesser, eliminate A and B)   Go for T = 12 --&gt; S = 30*12= 
<gadget id="calculator">30*12</gadget>
<output>360</output>
360 ---&gt; 360+50 / 12+5= less than 25. Either you can now go further with T = 15 or mark E as the answer .   Check: T = 15 ---&gt; S = 30*15= 
<gadget id="calculator">30*15</gadget>
<output>450</output>
450 ---&gt; 450+50/20= 25.   ANSW15R:15
<result>E</result>
The present ratio of students to teachers at a certain school is 30 to 1. If the student enrollment were to increase by 50 students and the number of teachers were to increase by 5, the ratio of students to teachers would then be 25 to 1. What is the present number of teachers?