Questions

In each circle,lower number equals the product of the top two numbers, subtracting 3 for the left hand circle, 4 for the middle, and 5 for the right hand circle.

While extracting a float argument using va_arg we should have useed 

c = va_arg (ptr, double)

These mangrove or tidal forests are found in the submerged coastal plains of the Ganga. The name comes from the abundant sundari trees found here. 

Carbon monoxide is one of the major pollutant present in the world. The six most common pollutants include ozone, carbon monoxide, sulfur dioxide, lead, nitrogen oxides, and particulate matter.

Carbon monoxide is a common atmospheric pollutant. It is produced largely in combustion processes like in industries and in vehicles. It is a gas that cannot be seen nor smelled.

Sum of numbers in all individual boxes must be equal.

Here sum must be equal to 30.

=> x + 14 + 9 + 2 = 30 => x = 5.