Solving Q1 : What is y when x = 50? (the solution graph is attached below)
We can make a rectangle (in red color on solution graph) to find the value of y corresponding to x = 50. We can see that y-value lies between 200 and 250.
It is near about y = 225. Hence, option B is correct.
Solving Q2 : What is x when y = 300? (the solution graph is attached below)
We can make a rectangle (in red color on solution graph) to find the value of x corresponding to y = 300. We can see that x-value lies between 60 and 65.
It is near about x = 61. Hence, option A is correct.
Solving Q3 : Solve 17x = 3.

Hence, option A is correct i.e. x = 0.18