A circle has a radius of 7 cm. Calculate for the circle, the diameter, circumference, and area.

The diameter ($d$) of a circle is twice its radius ($r$).

The diameter is $\boxed{14 \text{ cm}}$.

b) Calculate for the circle, the circumference.

The circumference ($C$) of a circle is given by $C = 2\pi r$ or $C = \pi d$.
Using $C = 2\pi r$:

The circumference is $\boxed{44 \text{ cm}}$.

c) Calculate for the circle, the area.

The area ($A$) of a circle is given by $A = \pi r^2$.

The area is $\boxed{154 \text{ cm}^2}$.

28. The table below shows the frequency table of the distribution of time taken by learners in a class to complete a Mathematical question.

a) Calculate the mean time taken by pupils to complete the question.

The mean time taken is $\boxed{5.13 \text{ minutes}}$ (to 3 significant figures).

b) Pupils who took more than 5 minutes were given another question. A pupil was randomly chosen from the class. Find the probability that the pupil was given another question.

These are pupils who took 6, 7, or 8 minutes.
Number of pupils = (Frequency for 6 minutes) + (Frequency for 7 minutes) + (Frequency for 8 minutes)

From part (a), the total number of pupils is $\sum f = 39$.

The probability that the pupil was given another question is $\boxed{\frac{14}{39}}$.