What is the four digit number in which the first digit is 1/3 rd the second, the third is the sum of the first and second and the last is three times the second?

27 ducks are marching to the pond. 5 lose their way, 13 return, and 9 of them make it to the pond. What happens to the rest of them?

Alone I am 24th, with a friend I am 20.
Another friend and I am unclean.
What am I?

If 9999 = 4, 8888 = 8, 1816 = 6, 1212 = 0, then 1919 =?

A donkey - behind another donkey.
I'm behind the second donkey.
There is a whole nation behind me.
It's a murder described in a word. 

 If 1+9+8=1, what is 2+8+9?

You have a torch which needs 2 working batteries. You have 8 batteries but only 4 of them are working.

What is the least number of battery pairs you need to check to make sure you get the flashlight on?

Multiplication and addition of three numbers gives same result.

What are those numbers?

Our dear Admin has a locker in a bank.
But, he has forgot the key to open the locker.
Fortunately, he remembers some things which may help you to help him.
· Key is a four digits number (eg.1234 or 9876)
· Every digit is different
· It starts and ends with an odd number and has two even numbers in the middle.
· 19 and 519 go into it exactly.

What is the key which will open the locker?

How many 9's are there between 1 and 100?

What is the four digit number in which the first digit is 1/3 rd the second, the third is the sum of the first and second and the last is three times the second?

27 ducks are marching to the pond. 5 lose their way, 13 return, and 9 of them make it to the pond. What happens to the rest of them?

Alone I am 24th, with a friend I am 20.
Another friend and I am unclean.
What am I?

If 9999 = 4, 8888 = 8, 1816 = 6, 1212 = 0, then 1919 =?

A donkey - behind another donkey.
I'm behind the second donkey.
There is a whole nation behind me.
It's a murder described in a word. 

 If 1+9+8=1, what is 2+8+9?

You have a torch which needs 2 working batteries. You have 8 batteries but only 4 of them are working.

What is the least number of battery pairs you need to check to make sure you get the flashlight on?

Multiplication and addition of three numbers gives same result.

What are those numbers?

Our dear Admin has a locker in a bank.
But, he has forgot the key to open the locker.
Fortunately, he remembers some things which may help you to help him.
· Key is a four digits number (eg.1234 or 9876)
· Every digit is different
· It starts and ends with an odd number and has two even numbers in the middle.
· 19 and 519 go into it exactly.

What is the key which will open the locker?

How many 9's are there between 1 and 100?