When it's bad luck to meet a black cat?

Can you arrange four 9's and use at most 2 math symbols, to make the total 100?

Which of the following words don't belong in the group and why?
CORSET, COSTER, SECTOR, ESCORT, COURTS

Find the next number in the series below

21 32 54 87 131 ?

One day Jenifer meets the Lion and the Tiger in the Forest of Forgetfulness. She knows that the Lion lies on Mondays, Tuesdays, and Wednesdays, and tells the truth on the other days of the week. The Tiger, on the other hand, lies on Thursdays, Fridays, and Saturdays, but tells the truth on the other days of the week. Now they make the following statements to Jenifer:

Lion: Yesterday was one of my lying days.

Tiger: Yesterday was one of my lying days too.

What day is it?

It walks on 4 when its young, walks on 2 when it's older, and walks on 3 when its very old?

Can you find out what is missing?

1 3 5
2 4 ?

Hint: It's not six. Think out of the box.

Jessica is telling her friends this story and asks them to guess if it’s the truth or a lie: “There was a man sitting in a house at night that had no lights on at all. There was no lamp, no candle, and no other source of light. Yet, he sat in the house and read his book happily.” Her friends say she’s lying, but Jessica corrects them and says she’s telling the truth. Jessica’s story is true—but how?

Can you identify if it's a murder or a suicide ?

What is the next number in the series?

15 29 56 108 208 ?