If you say my name, I will no longer exist. What am I?

_ _ _ 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.

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

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

They are three errirs in this question. Can you find them?

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?

When my father was 31 I was 8. Now he is twice as old as me. How old am I?

An exterior architect is asked by a builder to plant seven trees in a manner that there are exactly six rows of trees in a straight line and each row has three trees in particular.

How will he do it?

What do you call a fish without an eye?

How many times do a clock's hands overlap in a day ?

Decode below three cipher riddles:

26 L of the A
7 D of the W
1000 Y in a M