What is next number in the pattern below:

131 517 192 123 ?

Can you write down eight eights so that they add up to one thousand?

There are people and strange monkeys on this island, and you can not tell who is who (Edit: until you understand what they said - see below). They speak either only the truth or only lies.
Who are the following two guys?
A: B is a lying monkey. I am human.
B: A is telling the truth.

I live in a bowl. I can swim. I have a tail. I also have fins and big eyes. What am I?

If a zookeeper had 100 pairs of animals in her zoo, and two pairs of babies are born for each one of the original animals, then (sadly) 23 animals don’t survive, how many animals do you have left in total?

In the Mexico City area, there are two Houses H1 and H2. Both H1 and H2 have two children each.
In House H1, The boy plays for Mexico Youth academy and the other child plays baseball.
In House H2, The boy Plays soccer for his school in Mexico and they recently have a newborn.

Can you prove that the probability of House-H1 having a girl child is more than that of House-H2?

What month of the year has 28 days?

Cristina was born in 1888. She just had her 30th birthday today how did that happen?

What does this rebus means ?

What demands an answer, but asks no questions