Replace the question mark with the correct number.

Can you think of a smallest +ve number such that if we shuffle the digits of the number, the new number becomes double the original number?

There are 100 bulbs in a room. 100 strangers have been accumulated in the adjacent room. The first one goes and lights up every bulb. The second one goes and switches off all the even-numbered bulbs - second, fourth, sixth... and so on. The third one goes and reverses the current position of every third bulb (third, sixth, ninth? and so on.) i.e. if the bulb is lit, he switches it off and if the bulb is off, he switches it on. All the 100 strangers progress similarly.

After the last person has done what he wanted, which bulbs will be lit and which ones will be switched off?

You bought me for dinner but never eat me. What am I?

Find the Next Number in the Sequence

2 9 3 1 8 4 3 6 5 7 ?

I cannot talk, but I always reply when spoken to. What am I?

If,

20 % 5 = 24

21 % 7 = 33

42 % 6 = 67

Then;

66 % 6 = ?

How can you tell a raw egg from a hard-boiled egg?

What goes up but never comes down?

Imagine you are in a room with no windows or doors. How will you get out?