Transform the word THINK into BRAIN while changing only one letter at a time in a manner that each of the word in the process is a real word!!!

What is the below Rebus indicate?

There are 2 people near the river and both of them want to get on the other side. The boat can only take one of them. But they got across.
How?

Sharpest vision can find the lamp in the desert. Are you one of them? Test your observation skills now!

A mile-long train is moving at sixty miles an hour when it reaches a mile-long tunnel. How long does it take the entire train to pass through the tunnel?

John walks into the daily grocery shop and steals a $100 bill from the shop. An hour later John returns to the shop and buys some daily products for $40. John pays the owner the $100 bill and therefore the owner returns him $60.

How much money did the owner lose?

With pointed fangs I sit and wait; with piercing force I crunch out fate; grabbing victims, proclaiming might; physically joining with a single bite. What am I?

A plane crashed between the border of Mexico and America. Where do you bury the survivors?

Living above a star, I do not burn
Eleven friends and they do not turn
I can just be visited in a sequence, not once or repeatedly
PQRS are my initials
Can you tell my name accurately?

Which is the smallest number that you can write using all the vowels exactly once?