Question 612819
discrete means there's a finite possible set of numbers in the interval.
continous means there's an infinite possible set of numbers in the interval.
the answer appear to be:
a.  continuous
b.  continuous
c.  discrete
d.  continuous

for (a), there are an infinite number of possible times limited only by the ability of the stopwatch to record them.  
for (b), the number of fractions possible is infinite because you can always get a fraction between any 2 fractions.
example:
a fraction between 1/4 and 1/3 would be 3/8 because 1/4 = 2/8 and 1/2 = 4/8.
a fraction between 1/8 and 1/4 would be 3/16 because 1/8 = 2/16 and 1/4 = 4/16.
a fraction between 1/16 and 2/16 would be 3/32 because 1/16 = 2/31 and 2/16 = 4/32.
no matter how fine  you make the fraction, you can always generate another fraction that is finer than that.
for (c), there are a finite number of possibilities and no more than that.
you can get any combination of 1 through 6 added to any combination of 1 through 6 but no more.
for (d), the length of the broad jump has an infinite number of possible measurements limited only by the ability of the measuring equipment.