What happened when the wheel was invented?

If it took eight men ten hours to build a wall, how long would it take four men to build it?

Can you write down eight eights so that they add up to one thousand?

1 + 9 + 8 = ?
considering, 28 + 8 + 92 = 10

There is a barrel with no lid and some wine in it. 'This barrel of wine is more than half full,' said Curly. 'No it's not,' says Mo. 'It's less than half full.' Without any measuring implements and without removing any wine from the barrel, how can they easily determine who is correct?

If in a code language, DISTANCE is written as IDTUBECN and DOCUMENT is written as ODDVNTNE, the how will THURSDAY be coded as in the same language?

What is the four-digit number in which the first digit is one-third the second, the third is the sum of the first two, and the last is three times the second?

A man is trapped in a room. The room has only two possible exits doors. Through the first door there is a room constructed from magnifying glass. The blazing hot sun instantly fries anything or anyone that enters. Through the second door there is a fire-breathing dragon. How does the man escape?

Find The Next Number In The Sequence

30 10 15 13 0 16 -15 ?

Can you find out the missing number in the grid?