Quickly Solve this riddle

7 - 4 + 3 * 0 + 1 = ?

A cricket has 6 legs, a squirrel has 4 legs and a spider has 8 legs.

In a local zoo, it was found that the total number of legs is 612. Also, there are equal number of each of the above animals/insects.

Can you find out how many animals are there in the zoo?

A girl is twice as old as her brother and half as old as her father. In 50 years, her brother will be half as old as his father. How old is the daughter now?

How many pluses should we put between the digits of 987654321 to get a total of 99, and where?

A newspaper is supposed to have 60 pages.Pages 14 and 21 are missing from the newspaper.

Can you tell me , Which other pages won't be there as well ?

What is the largest number you can write with just 3 digits?

A mules travels the same distance daily.
I noticed that two of his legs travels 10km and the remaining two travels 12km.
Obviously two mules legs cannot be a 2km ahead of the other 2.

The mules is perfectly normal. So how come this be true ?

Can you find out the remainder when 3^300 is divided by 5?

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

Can you find out which number multiplied by itself will give the output as 12345678987654321?