Last Updated on May 11, 2023
GMAT OFFICIAL GUIDE PS
Solution:
We are given that a certain experimental mathematics program was tried out in 2 classes in each of 32 elementary schools and involved 37 teachers. Thus, there were a total of 2 x 32 = 64 classes under this program.
If we let a = the number of teachers teaching one class, b = the number of teachers teaching two classes, and c = the number of teachers teaching 3 classes, we can create the following equations:
a + b + c = 37
a + 2b + 3c = 64
Subtracting equation 1 from equation 2, we have:
(a + 2b + 3c = 64) – (a + b + c = 37)
b + 2c = 27
2c = 27 – b
c = (27 – b)/2
We see that c is the GREATEST when b = 1, and thus (27 – 1)/2 = 26/2 = 13.
We also see that c is the LEAST when b = 27, and thus (27 – 27)/2 = 0/2 = 0.
So the range of values of n is 0 to 13.
Answer: A
