I am sure no one can have two things for dinner. what are they?

Replace the question mark with the correct number in the below-given picture?

If,
29 - 1 = 30
9 - 1 = 10
14 - 1 = 15

Based on similar logic, Can you prove that the below algebraic equation is true?
11 - 1 = 10 ?

Can anyone tell me a word in the English dictionary which has a silent 'z'?

How is the moon similar to a dollar?

A man who was outside in the rain without an umbrella or hat didn’t get a single hair on his head wet. Why?

Twenty frogs are sitting on a log floating on the surface of a river. Two of them decide to jump off into the water.

How many frogs are there on the log at this moment?

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?

As a whole I am both
safe and secure.

Behead me and I become
a place of meeting.

Behead me again and I am
the partner of ready.

Restore me, and I become
the domain of beasts.

What am I?

If all Goats are Sheep and all Sheep are Deers, are all Deers Goats ?