Questions

Chromium is the chemical element that is used as a shiny metal on the automobile bodies especially for trim.

There are different colors that are used for different signs on the maps. The typical color standard for topographic maps depicts contours in brown, bodies of water in blue, boundaries in black, and grids and roads in red. Topographic maps may use different colors to represent area features.

Black represents man-made objects or cultural features like roads, bridges, borders, etc...

Here in the given puzzle,

2 x (2 + 2) = 8

3 x (3 + 3) = 18

4 x (4 + 4) = 32

5 x (5 + 5) = 50

Similarly,

6 x (6 + 6) = 72.

Kachchh district is the largest in India in terms of territorial extent, located in the state of Gujarat.
The second largest district is Leh in Jammu & Kashmir.