7) We know that there are 4 boys and 12 girls in Mr Jhonson's club and there are 6 boys in Ms Greene's cub.
To know the number of girls in Ms Greene's club we must solve for x the next equation
[tex]\begin{gathered} \frac{4}{12}=\frac{6}{x} \\ 4x=12\cdot6 \\ x=\frac{72}{4}=18. \end{gathered}[/tex]So, there are 18 girls in Ms Greene's club.
8) We know that the temperature decrease by 12°C.
So, if the original temperature was 12°C the final temperature is represented by
[tex]\begin{gathered} \text{ FinalTemperature=temperature at 12:00 - 12\degree{}C} \\ \text{ FinalTemperature=12\degree{}C-12\degree{}C} \end{gathered}[/tex]Finally, the answer is letter A.
9) To know the anwer we must solve 7/12
[tex]\frac{7}{12}=0.58333333[/tex]as the last number is repeated infinite times, we must write the answer as a periodic decimal.
Finally, the aswer si
[tex]0.58\bar{3}[/tex]So, the answer is letter B