Question

a plane is flying at a height of 4500m above the sea level. at a particular point ,it is exactly above submarine floating 1100m below sea leavel. what is the vertical distance between them?

Answer 1

the vertical distance between them is 4500m + 1100m
➡️ 5600m
is that ok......

see,
above the sea level refers to the distance or the height above the level of the sea.( the height at which the flight is flying)

And below the sea level refers to the distance below to the level of the sea.( the distance below
which the submarine is moving)...