Questions

Survey of India publishes maps and the unrestricted category maps can be obtained at very affordable prices from its several Geospatial data centers. Restricted category maps require due approval from government authorities. Many other rules govern the sale and use of Survey of India maps. Only an Indian citizen may purchase topographic maps and these may not be exported from India for any reason.

The Survey of India is India's central engineering agency in charge of mapping and surveying, set up in 1767. Its members are from Survey of India Service cadre of Civil Services of India. It is headed by the Surveyor General of India.

The given letter equation implies that, 

7 C in the R = 7 Colours in a Rainbow.

In the given puzzle the logic is

2 x 1 + 1 = 2 + 1 = 3

3 x 2 + 2 = 6 + 2 = 8

4 x 3 + 3 = 12 + 3 = 15

5 x 4 + 4 = 20 + 4 = 24

6 x 5 + 5 = 30 + 5 = 35

Similarly,

7 x 6 + 6 = 42 + 6 = 48

7 = 48.