Quickly Solve this riddle

7 - 4 + 3 * 0 + 1 = ?

Christina is practising her dance steps along with her friends. In a particular sequence, all of them form a row. At that point, Niharika is standing in the 4th position from either end of the row.
Can you find out how many girls are practising together?

It comprises roots which nobody sees,
Much taller than those trees,
Up and up it goes,
Still it never grows?

Analyze and find the missing item in the sequence:
16, 06, 68, 88, __, 98

There was an aeroplane crash, every single person died, but two people survived. How is this possible?

What number do you get when you multiply all of the numbers on a telephone's number pad?

There are a number of books on a shelf. If one book is the 4th from the left and 6th from the right, how many books are on the shelf?

My first is in chocolate but not in ham. My second is in cake and also in jam. My third at tea time is easily found. Altogether, this is a friend who is often around. What is it?

Some friends went on a vacation to a resort. It was raining heavily and it kept raining for thirteen days.

When it rained in the morning, the afternoon was beautiful and when it rained in the afternoon, the day was blessed with a clear morning.

Overall, the friends experienced eleven nice mornings and twelve nice afternoons. Can you find out the number of days they spent on vacation?

A beggar on the street can make one cigarette out of every 6 cigarette butts he finds. After one whole day of searching and checking public ashtrays the beggar finds a total of 72 cigarette butts. How many cigarettes can he make and smoke from the butts he found?