After studying the maps that you posted with the question, the map that shows both the dominate air pressure over India can be found easily. So the air pressure system that forms in the summer and the direction of the surface winds around the air pressure system can be found in map number 1.
The Cascade Mountains create a rain shadow. Hope this helps!
So with the first number in each set, look on the x axis or the horizontal line for the number. For example, 2 1/2 on the horizontal line or x axis is on the right side, next to the two and the x. The second number is on the vertical side, and the same thing. In this case, -1 1/2 would be on the bottom in between the -1 and the arrow.
Now find the place where the two intersect on the coordinate plane, and put a dot there to mark the coordinate.
I myself would go with Central
