Can you find a pattern and the missing number in the series given below?

100, 155, 258,? , 584, 819.

Find the combined weight of the Cat, Dog and Rabbit in the given picture.

What can run but never walks, has a mouth but never talks, has a head but never weeps, has a bed but never sleeps?

Consider this about a word: The first two letters signify a male, the first three letters signify a female, the first four letters signify a great, while the entire world signifies a great woman. What is the word?

How can one talk without saying a single word?

There is a shop where written:
Buy 1 for $1
10 for $2
100 for $3
I needed 999 and still only paid $3. How could this be financially viable for the shop-keeper?

Find the next number in the series below

21 32 54 87 131 ?

Find the missing letter in the last circle logically in the given below picture.

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!!!

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?