Two friends – Layla and Liv went on dinner together.

Answer At The Last Slide

They ate their favorite dishes and then both of them ordered iced tea.

Layla drank iced tea faster than Liv.

By the time Liv finished her first iced tea, Layla already finished 5.

All of a sudden Liv died while Layla survived.

However when the police was investigating, 

They found that both drinks were poisoned.

Still how come Liv died and Layla didn’t ?

     ANSWER The poison was in the ice.  Liv waited for ice to melt so her drink was fully poisoned.  While Layla didn’t let ice to melt which is why her drink was less poisonous.