75. Among the applicants who passed the entrance exams to a technical university, "excellent" grades were received by: in mathematics - 48 people, in physics - 37, in literature - 42, in mathematics or physics - 75, in mathematics or literature - 76, in physics or literature - 66, in all three subjects - 4. How many applicants received only one "excellent" grade? Exactly two "excellent" grades? At least one "excellent"?
$\triangle$ Let's apply Euler circles. Let M, Ph, and L denote the sets of applicants who have scored "excellently" in mathematics, physics, or literature, respectively; these sets have 48, 37, and 42 elements, respectively. The common part of all three sets has 4 elements. Let $a, b, c, x, y, z$ denote the number of applicants who received an "excellent" grade in one or two of the three subjects (Fig. 28).

Using the diagram, the conditions of the problem can be represented by the following equations:

$$
\left\{\begin{array}{l}
a+x+y=44 \\
b+x+z=33 \\
c+y+z=38 \\
a+b+x+y+z=71 \\
a+c+x+y+z=72 \\
b+c+x+y+z=62
\end{array}\right.
$$

This results in a system of six equations with six unknowns. However, we need not the unknowns $a, b, c, x, y, z$, but the sums $a+b+c$ and $x+y+z$. To find these, we first add the first three equations and then the last three equations:

$$
\left\{\begin{array}{l}
a+b+c+2(x+y+z)=115 \\
2(a+b+c)+3(x+y+z)=205
\end{array}\right.
$$

Considering the last system of equations as a system with two unknowns, we find the sums of interest from it:

$$
a+b+c=65, x+y+z=25 \text{. }
$$

Answer: $65, 25, 94$.