This can be solved using a Venn diagram (below).
A=Employees without the named qualifications.
B=Only degree
C=Only CPA
D=Only diploma
E=Degree+diploma only
F=CPA+diploma only
G=CPA+degree only
H=All three qualifications
Now we can put in some numbers.
A+B+C+D+E+F+G+H=60 (employees)
B+E+G+H=19 (degree)
D+E+F+H=18 (diploma)
C+F+G+H=50 (CPA)
H=9
E+H=G+H=13, so E=G=13-H=4; F+H=11, so F=2; C=50-2-4-9=35; D=18-4-2-9=3; B=19-4-4-9=2.
A=60-2-35-3-4-2-4-9=1.
(a) A=1 employee with none of the qualifications.
(b) C=35 employees with CPA only.
(c) E=4 employees with degree and diploma only.
(d) B+C+D=2+35+3=40 employees with only one qualification.
(e) E+F+G=4+2+4=10 employees with only two qualifications.