An proper fraction is a fraction where the denominator is larger than the numerator.
An improper fraction is a fraction where the numerator is larger than or equal to the denominator.
a. 4/16
The denominator is 16. The numerator is 4. The denominator is larger than the numerator; thus, this is a proper fraction.
b. 75/70
The denominator is 70. The numerator is 75. The numerator is larger than the denominator; thus, this is an improper fraction.
c. 2/15
The denominator is 15. The numerator is 2. The denominator is larger than the numerator; thus, this is a proper fraction.
d. 6/6
The denominator is 6. The numerator is 6. The numerator is equal to the denominator; thus, this is an improper fraction.