I think a would be the best answer for the preposition
Ach culture will have its own set of belief systems and practices. Because each culture is different, the issues that resonate across cultures will be the opposing beliefs and practices. For example, religion is often an issue across cultures, because each culture is sure that their religion is the correct one, and that other cultures should follow suit. In response to these issues, arguments are developed to attempt to prove once and for all that the belief systems in a particular culture are right, while the opposing belief systems in other cultures are wrong. In the case of religion, one would try to provide evidence for Christianity, for example, while at the same time negating the importance of religions like Buddhism or Judaism.
Given:
Potential difference between capacitor plates = 2.6 V
Dielectric constant of paper , K = 3.7
Solution:
When air is filled, let the potential difference between capacitor plate be V'
Now, after being disconnected from the battery, the charge stored in the capacitor will remain constant
And when dielectric is introduced between the capacitor plates, the potential difference will be reduced by k times a:
V = 
Therfore, V' = KV = 3.7 × 2.6 = 9.62 V
The resulting potential difference of the capacitor, V' = 9.62 V
First replace k with 4 and you get
5*4+6
now multiply 5*4 (order of operations) and you get
20+6
Now just add and you get
26
Hope this helped :)
