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

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

In case you were starting to feel confident, this one was meant for third graders in Vietnam. The answer is 66, but we don't blame you for scratching your head about how they got there.

Using Only Five 5's and any mathematical operator make sum as 37

In an Art Gallary, When the clock hit 11 am, Artist hung the painting number 30. When it struck 4 pm, he hung painting number 240 and when it struck 7:30 pm, he hung painting number 315.

Can you determine, which painting number will he hang when the time is 9:20 pm?

Do You See It?

Keyboard words are not in alphabetical order, Why?

Until it is measured, not known. Yet how you miss it when it has gone. What is it?

In the image below, you can see two glasses and two matchsticks.You need to move four matchsticks in such a manner that the crosses come inside the glasses. Note: you cannot move the crossed.

A bomb exploded in a room full of married couples and no one died. How?

Find the mistake in the below maths equations

A = 2
A(A-1) = 2(A-1)
A2-A = 2A-2
A2-2A = A-2
A(A-2) = A-2
A = 1