Find The Next Number In The Sequence

30 10 15 13 0 16 -15 ?

How many letters are in the alphabet?

Can you find out the total number of triangles in the given figure?

Decode the below four famous ciphers:

8P of the SS
1M of the E
1S of the SS
60M in 1H

In a town, there are over 100 flats.
Flat-1 is named first flat.
Flat-2 is named second flat.
Flat-3 is named third flat.

A visitors 'Victor' decides to walk through all the flats, he finds all the flats except flat-62.
Victor later founds that the local of the town have given it another name.

What is the name of the Flat?

What occurs twice in a week, once in a year but never in a day?

What does below rebus means ?

John is selling fruits.
He sells grapes at $30, Dates $25, and a Wolfberry $45.
At what price does he sell fig?

PS: Logical Thinking

_ _ _ IE _ _
_ _ _ IE _
_ _ IE _ _
_ _ IE _
_ _ _ _ IE

Like you see, some letters have gone missing from these words that contain the IE pair at some or the other place. The letters that will be used to fill the blanks are given below. Use them and form meaningful words. Can you do that?

A, C, D, F, H, K, L, M, N, N, O, R, R, S, S, S, T, T, Y and Y.

In which direction should the missing arrow point?