Ratio 

The number of 10 seat room = x 

The number of 20 seat room = 40- x

According to question

$$\begin{gathered} 10x+20(40-x) = 600 \\ \Rightarrow 10x+800- 20x = 600 \\ \Rightarrow -10x=600-800=-200 \\ \therefore x=\frac{-200}{-10} =20 \end{gathered}$$

Number of 10 seat room = 20 and number of 20 seat room = 40-20=20. 

The ratio of the number of 10 seat room to the number of 20 seat room = 20 : 20= 1 : 1. ans.

Given, total football players 85

Do not score a goal = 85 - 42 = 43 players

Do not receive a yellow card = 85-54 = 31 

players Do not score a goal or don't receive yellow card or do not do either = 43 +31-5=69

Number of players who scored a goal and received a yellow end = 85 - 69 = 16

Required fraction = 16/85 ans.