Find the next number in the sequence

1, 2, 6, 21, 88, __?

I am eight letters long - "12345678"
My 1234 is an atmospheric condition.
My 34567 supports a plant.
My 4567 is too appropriate.
My 45 is a friendly thank-you.
My 678 is a man's name.

What word am I?

There are three Athletes (John, Tarun and Harish) and their individual Coaches (Jacob, Meenaxi and Priyanka) standing on the shore.
No Coach trusts their Athlete to be near any other Coach unless they are also with them.
There is a boat that can hold a maximum of two persons.
How can the six people get across the river?

Can you solve this amazing hard number series problem?
7, 8, 10, 12, 16, 18 ?

How will you measure 15 minutes using two hourglasses of 7 minutes and 11 minutes respectively?

Can you solve the below tricky visual equation?

I am weightless, but you can see me. Put me in a bucket, and I'll make it lighter. What am I?

I am the fastest animal but cannot climb the tree. What am I?

To attend world science seminar, A famous chemist from Mexico visit
London. In the lab, the scientist was killed and his six assistants were under suspicion of killing the chemist.
Name of six assistants: Austin, Wayne, Dege, Oscaru, Lingard, and Rojo.
He left a note "76-20-44 79-16-22-7"

A local detective Jack was called to solve the case,

After reading the note, Jack instantly asked the police to arrest the murderers.

Who are the murderers?

A blonde put eyeliner on her head. Why?