Commonly asked number puzzles in all kind of interviews. Sequence number, missing number, series number problems etc.

Find a 10-digit number where the first digit is how many zeros in the number, the second digit is how many 1s in the number etc. until the tenth digit which is how many 9s in the number.

**Answer:**6210001000

How can I get the answer 24 by only using the numbers 8,8,3,3.

You can use add, subtract, multiply, divide, and parentheses.

**Answer:**

8/(3-(8/3))

= 8/(1/3)

= 24

A pearl necklace has 33 pearls with the largest and most valuable in the middle.

Starting from one end, each successive pearl is worth $100 more than the one before (up to the middle one), but starting from the other end each pearl is worth $150 more than the one before, up to the big pearl. The whole necklace is worth $65 000.

What is the value of the middle pearl?

**Answer:**The value of the central pearl is $3000.

The pearl at one end (from which they increased in value by $100) : $1400.

The pearl at the other end : $600.

What number should replace the question mark to a definite rule?

147,159,174,186, ?

**Answer:**201 (add digits to previous number).

If I had one more sister I would have twice as many sisters as brothers. If I had one more brother I would have the same number of each. How many brothers and sisters have I?

**Answer:**Three sisters and two brothers.

This can be solved by simple deduction, but if algebra is used let x be the number of sisters and y the number of brothers :

x+ 1= 2y

y+ 1= x

Therefore, y + 1+ 1= 2y

so y =2 or x + 1= 2x – 2

so x = 3.

Which number is the odd one out?

159

248

963

357

951

852

**Answer:**248

In the rest there is the same difference between each digit, eg : 8 (–3) 5 (–3) 2.

If a car had increased its average speed for a 210 mile journey by 5 mph, the journey would have been completed in one hour less. What was the original speed of the car for the journey?

**Answer:**30 mph.

In a game of eight players lasting for 70 minutes, six substitutes alternate with each player. This means that all players, including the substitutes, are on the pitch for the same length of time. For how long?

**Answer:**40 minutes.

(70 × 8)÷ 14.

Total time for eight players = 70 × 8 = 560 minutes.

However, as 14 people are each on the pitch for an equal length of time, they are each on the pitch for 40 minutes (560 ÷ 14).

For more maths puzzles **click here**.

For puzzle 1: another solution is: 8000000010

here second digit is 8″0″00000010 is zero which should be 1 as there is one 1 , but that would make two 1′s in total which is not possible.

hence only answer is 6210010000