Hard Riddles

Hard riddles with answers are a true test of your brain power, reasoning and comprehension. You are sure to find these tough difficult riddles both challenging and puzzling. While these hard riddles and answers may drive you a little crazy sometimes, they may surprise you in the way they force you think out of the box.

Two Water Lilies

Water lilies grow extremely rapidly. In one pond, a water lily grew so fast that each day it covered a surface area double that of the area it had covered the previous day. At the end of the 30th day, it had covered the pond entirely. How long do you think it will take for two such water lilies to cover the whole pond?

Riddle Answer