To find the number of minutes required for $k$ calculations, we can use a step-by-step conversion of rates and units.
1. Determine the rate of the computer

The computer performs $c$ calculations in $s$ seconds. Its rate (calculations per second) is:

$$
\(\text { Rate }=\frac{c}{s} \text { calculations } / \text { second }\)
$$

2. Calculate the time needed in seconds

To find the time required to perform $k$ calculations, we divide the total number of calculations by the rate:

$$
\(\begin{gathered}
\text { Time }(\text { seconds })=\frac{\text { Target calculations }}{\text { Rate }} \\
\text { Time }(\text { seconds })=\frac{k}{\frac{c}{s}} \\
\text { Time }(\text { seconds })=\frac{k s}{c}
\end{gathered}\)
$$

3. Convert seconds to minutes

Since there are 60 seconds in a minute, we divide the total number of seconds by 60 :

$$
\(\begin{aligned}
\text { Time (minutes) } & =\frac{\frac{k s}{c}}{60} \\
\text { Time }(\text { minutes }) & =\frac{k s}{60 c}
\end{aligned}\)
$$


Conclusion
Comparing this to the given choices:
- A. $\(\frac{60 k s}{c}\)$ (Multiplied by 60 instead of dividing)
- B. $\(\frac{k s}{c}\)$ (This is the time in seconds, not minutes)
- C. $\(\frac{k s}{60 c}\)$ (Correct)
- D. $\(\frac{60 c}{k s}\)$ (Inverted the rate)
- E. $\(\frac{k}{60 c s}\)$ (Incorrect placement of variables)

Correct Option: C. $\(\frac{k s}{60 c}\)$