#### Answer

a)Continuous.
b)Discrete.
c)Discrete.
d)Discrete.

#### Work Step by Step

Discrete data are always whole numbers, whereas continuous data can take infinitely many values on a given interval. Hence:
a)Exact breaking values cannot be only whole numbers, hence they are continuous.
b)Rounded breaking values are always whole numbers, hence they are discrete. c)The number of students is always whole numbers, hence they are discrete. d)The number of rolls is always whole numbers, hence they are discrete.