Can you find out the remainder when 3^300 is divided by 5?

An American nightclub called 'The Coconut Grove' had a terrible fire in which over 400 people died. A simple design flaw in the building led to a high death toll. Subsequently, regulations were changed to ensure that all public buildings throughout the country eliminated this one detail, which proved deadly. What was it?

What does the following represent?

N N N N N N N

A A A A A A A

C C C C C C C

Can you place three balls such that the equation shown in the picture holds true?

Decode below rebus
D
N
A
T
S , D

An express train takes 3 seconds to enter the tunnel which is 1 km long.
If it is travelling at 120 km an hour, how long will it take to pass completely through the tunnel?

A prisoner is told: "If you tell a lie, we will hang you and if you tell the truth, we will shoot you." What did the prisoner say to save himself?

Can you find a pattern and the missing number in the series given below?

100, 155, 258,? , 584, 819.

I’m light as a feather, yet the strongest person can’t hold me for five minutes. What am I?

Can you solve the tricky chess rebus puzzle below by ciphering the hidden meaning?