What internal condition is being maintained by the dilation and construction of pupils when lights are turned off and on?

I’m doing some practice exam questions for biology, and i’m not sure how to do these 3 parts to the question.

Lola needs to sign 6 invitations. using stopwatch that measures time to tenths of a second, it takes lola 5.3 seconds to sign her full name. going by the accuracy of the stopwatch, which is the most accurate determination for the number of minutes lola needs to sign all 96 invitations

If a strand of dna has 35% thymine. what is the percentage of cytosine, adenine, guanine?