What is dramatic irony?
audience knows something the characters don’t know
author exaggerates a situation in the plot
event is the opposite of what is expected
theme summarized in the resolution

What is dramatic irony?  

Audience knows something the characters don’t know

check your question

onto a large boat, and mark the water level that the boat sinks to. then, take the elephant out and put a bunch of marked weights onto the boat until it reaches the same water level. add up the masses of the weights to get the weight of the elephant.