eqautorial diameter of earth = 40075 km .

24 hour time for 1 spin .


speed at equator =( 40075 / 24 ) 1670 km/h.


now at any latitude


just take cos( ) of latitude and multiply it with speed at equator.


hence cos(45)= 0.707

so 0.707 x 1670 = 1180 km/h .


1180.7 is correct option


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question 14 is none of these ( its karst drainage) http://en.wikipedia.org/wiki/Karst_topography ( i thnik)