the work and answer provided are correct, the simpler way of doing it is
1)
1/6 page written in 1/12 of a minute
to write a full page, you would need to write 1/6, 6 times
so,
[tex]\frac{1}{6} \time 6 = 1[/tex]
and
[tex]\frac{1}{12} \times 6 = \frac{6}{12} = \frac{1}{2} [/tex]
so it takes 1/2 of a minute to write a full page, there are 60 seconds in a minute, 1/2 of 60 seconds is 30 seconds
same process works for question 2(use 3 instead of 6 though)