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!!!

I am the largest in my family of fifty.
The youngest of our family lives separately from the rest of the family and so do I.
I am regarded as harsh and tough.
I am so large, you cut me in two equal halves,
each half would still be larger than the second largest member of the family.
Who am I?

What is at the end of a rainbow?

O_er_t_o_

Complete the missing letters of the given word.

I taste better than I can smell. Who am I?

Two in a corner, one in a room, zero in a house, but one in a shelter. What am I?

It is raining today at 11:59 am. What is the probability of sunny weather after 72 hours?

Dwayne Johnson was running away with the loot from a heist in his car along with Vin Diesel. One tire was punctured and he dropped down to replace it. While changing the wheel, he dropped the four nuts that were holding the wheel and they fell into a drain. Vin Diesel gave him an idea using which they were able to drive till the rendezvous point.

What was the idea ?

How can one talk without saying a single word?

If 21x = 79x, what is the value of x?