BRAIN TEASERS

1. BINGO
A group of us were playing Bingo. I noticed something very interesting. There were different Bingo cards with no two cards having the same set of numbers in corresponding column or row. The centre of course was a free space. How many such cards are possible, can you tell?
2. Find out the Sum
What is the sum of al numbers between 100 and 1000 which are divisible by 14?
3.. A Pair of Palindromes
Multiply 21978 by 4. Now see if you can find a pair of palindromes.
4. Count the Digits
Can you find a number which added to itself one or several times will give a total having the same digits as that number but differently arranged and after the sixth addition will give a total of all nines?
5. Prime Number
Do you know which is the largest known prime number?
6. Continue the Series
1, 3, 6, 10 Name the next three numbers in the series
7. Smallest Positive Prime
Which is the smallest positive prime which is some multiple of seven less than a cube of a counting number less than ten?
8. Do You have Change?
Can you change a rupee note in such a way that there are exactly fifty coins? No 2 paisa coin?
9. A Probability Problem
Is it possible that there are 53 Tuesdays in a non-leap year? What is the probability?

ANSWERS
1. 1365
2. 35392
3. 4*21978=87912
4. 142857
5. 170 1411 83460469231731687303715884 105 727
6. 15 21 28 .. . .
7. 7
8. 45 PAISE, 2 FIVE PAISE, 2 TEN PAISE AND 1 TWENTY FIVE PAISE.
9. 1/7TH