I never stop running even when I standstill. If I am formed by joining two identical bodies together, can you guess who I am?

In a contest, four fruits (an apple, a banana, an orange, and a pear) have been placed in four closed boxes (one fruit per box). People may guess which fruit is in which box. 123 people participate in the contest. When the boxes are opened, it turns out that 43 people have guessed none of the fruits correctly, 39 people have guessed one fruit correctly, and 31 people have guessed two fruits correctly.
How many people have guessed three fruits correctly, and how many people have guessed four fruits correctly

Can you find out the number that should replace the question mark with a valid reason?

Speaking of rivers, a man calls his dog from the opposite side of the river. The dog crosses the river without getting wet, and without using a bridge or boat. How?

Distances from you to certain cities are written below.

BERLIN 200 miles

PARIS 300 miles

ROME 400 milesAMSTERDAM 300 miles

CARDIFF ??? miles

How far should it be to Cardiff ?

By what process could you make a 'Tea-Table' into food?

The following alphametic has only one solution. Can you find it?
ENLIST + SILENT + LISTEN = ANAGRAM

PS: You may start the number from 0.

Can you place three balls such that the equation shown in the picture holds true?

How will you measure 15 minutes using two hourglasses of 7 minutes and 11 minutes respectively?

I have cities, but no houses. I have mountains, but no trees. I have water, but no fish. What am I?