No point on Earth can have both an east and a west coordinate. Since you called
the first number a "latitude", it must be a north or south latitude.
If you meant to say 15 North / 12 west, the point is located in the Pacific Ocean,
about 1,345 miles due south of Goleta, California, and about 1,820 miles due west
of the coast of Mexico.
If you meant to say 15 South / 120 west, that point is also in the Pacific Ocean,
about 3,420 miles south of Goleta, and 2,970 miles due west of the coast of Peru.
Chad
Japan
Australia
Russia
Antarctica is located 0 degrees north and 40 degrees east.
About 20 degrees east latitude to 40 degrees east latitude.
It is on the country of Gabon
Since California is located in USA, the nearest country east of USA and at 40 degrees north latitude is Portugal.
Finland
Chad
Kenya.
Japan
Madagascar
Mexico
Australia
india
India