In a school, 25 % of the teachers teach basic math. If there are 50 basic math teachers, how many teachers are there in the school?
When we say that 25 % of the teachers teach basic math, we mean 25% of all teachers in the school equal number of teachers teaching basic math Since we don't know how many teachers there are in the school, we replace this with x or a blank However, we know that the number of teachers teaching basic or the percentage = 50 Putting it all together, we get the following equation: 25% of ____ = 50 or 25% × ___ = 50 or 0.25 × ____ = 50 Thus, the question is 0.25 times what gives me 50 A simple division of 50 by 0.25 will get you the answer 50/0.25 = 200 Therefore, we have 200 teachers in the school In fact, 0.25 × 200 = 50
In a class of 40 students, 12 enrolled for both English and German. 22 enrolled for German. If the students of the class enrolled for at least one of the two subjects, then how many students enrolled for only English and not German?
Let A be the set of students who have enrolled for English and B be the set of students who have enrolled for German. Then, (A U B) is the set of students who have enrolled at least one of the two subjects. As the students of the class have enrolled for at least one of the two subjects, A U B = 40 We know A U B = A + B - (A n B) i.e, 40 = A + 22 - 12 or A = 30 which is the set of students who have enrolled for English and includes those who have enrolled for both the subjects. However, we need to find out the number of students who have enrolled for only English = Students enrolled for English - Students enrolled for both German and English = 30 - 12 = 18.
Find the x intercept of the graph of the equation . 2x - 4y = 9
Given the equation 2x - 4y = 9 To find the x intercept we set y = 0 and solve for x. 2x - 0 = 9 Solve for x. x = 9 / 2 The x intercept is at the point (9/2 , 0).