## Funny Questions and Unexpected Answers at Tech Job Interview

May 17, 2013 Leave a comment

Brain Teaser Interview Questions And Answers on Amazon

Brain Teaser Interview Questions And Answers on iTunes

Math and Logic Puzzles

December 16, 2012 Leave a comment

**SMS** stands for **Short Math Situation**. The SMS questions are limited to 64 characters.

61. I cut & folded a shape of 1m square. What’s the largest volume? Answer

62. Make 33 by using three 3s and any math operators. Answer

63. How would you measure 4 liters with 3 and 5 liter buckets? Answer

64. Find 2 fractions made of 10 different digits. They add up to 1. Answer

65. Find the largest 2-digit perfect number. Answer

66. Find the maximum number of points of intersection of N circles. Answer

67. How do you cut a round cheese into 8 equal pieces with 3 cuts? Answer

68. Find the smallest 10-digit integer with only 2 digits the same. Answer

69. How many digits did I write to number 100 pages? Answer

70. How many squares can I form with 8 matchsticks? No overlap. Answer

71. What is the sum of the first 99 consecutive integer numbers? Answer

72. How many crosspieces do I needed to separately enclose 4 lambs? Answer

73. A Z D W G Find the next letter in the sequence. Answer

74. How many 4-digit passwords are possible if I use only 2 digits? Answer

75. How many 2-digit integers have the sum of the digits equals 10? Answer

76. The number A4321 is divisible by 9. Find the digit A. Answer

77. How thick is a plait of 200 hairs which diameter is 0.02 mm? Answer

78. What is the creases’ net on a paper folded in half 4 times? Answer

79. Find the smallest sum of 2 integers. Their product is 1000. Answer

80. What is the probability that two random dominos match? Answer

81. How many squares can be formed using seven matchsticks? Answer

82. Cut a rectangular piece of cheese with a hole in 2 equal parts. Answer

83. I met two kittens. What is the probability that they are boys? Answer

84. What number of spots appears more frequently on dominoes? Answer

85. Find 4 different integers if their product is 792? Answer

86. How many one-dollar bills completely cover a square mile? Answer

87. How many separate regions do three overlapping triangles form? Answer

88. How many letters are in the correct answer to this question? Answer

89. If 3 kids eat 3 kiwis in 33 seconds, how long do 9 kids eat 19? Answer

90. What sum of 2 digits is best to bet on? Answer

A+Click SMS Part 1 (questions 1 – 30)

A+Click SMS Part 2 (questions 31 – 60)

A+Click SMS Part 4 (questions 91 – 112)

December 14, 2012 1 Comment

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**SMS** stands for **Short Math Situation**. The SMS questions are limited to 64 characters.

31. How many diagonals does a regular octagon have? Answer

32. How many times heavier than a rabbit is an elephant? Answer

33. If you live 100 years, how many times will your heart beat? Answer

34. How many handshakes take place at a 100 men meeting? Answer

35. How many 4-digit pass codes are there? All digits are different. Answer

36. What part of the American flag is red? Answer

37. 99% of N nuts and 99% of a nut cost as much as all nuts. Find N. Answer

38. Find the smallest number divisible by all numbers from 1 to 20. Answer

39. Work out the sum of all the integers below 100. Answer

40. I buy 5 eggs for $1 and sells 1egg for $5. What’s my profit? Answer

41. How to split $4, $5, and $6 in a ratio of 1:2:3? Answer

42. What is the probability that two kittens are boys? Answer

43. What is the probability that one of 3 idiots survives in a duel? Answer

44. At least 2 Londoners have the same number of hairs. Is it true? Answer

45. Is it possible to plant 10 trees in 5 rows of 4 trees? Answer

46. How many triangles can I make with six line segments on a plane? Answer

47. Divide $1234 into the ratio 1:2:3:4. Answer

48. How much costs an item after three successive discounts of 20%? Answer

49. One of 240 coins is odd. How do you use a scale to find it? Answer

50. Tom’s income and spending are 7/8 that of Tim. Who saves more? Answer

51. How many 11-digit numbers can you make using 0, 1? Answer

52. Find the smallest integer that is 4 times the sum of its digits. Answer

53. How many 0s are at the end of the product of 2-digit integers? Answer

54. Guesstimate the number of your ancestors in 200 years. Answer

55. How many tennis balls can fit in a school bus? Answer

56. O T T F F S S What is the next letter in this series? Answer

57. Find the angle between two diagonals of a cube. Answer

58. For which capital letter would you use more paint? Answer

59. How many $1 bills are numbered from AB01234567 to AB11111111? Answer

60. What occurs once in a minute, twice in a week, once in a year? Answer

A+Click SMS Part 1 (questions 1 – 30)

A+Click SMS Part 3 (questions 61 – 90)

December 11, 2012 Leave a comment

Many car owners make decisions without any calculation. They use gut feelings and don’t spend time on math. However, small calculative efforts of 2-3 minutes can help to inform wise decisions and give the owner the confidence that they are making the best choice.

Here are real-life examples:

We calculate how many miles we can drive with a half tank.

We calculate the value of a car after owning it for several years.

We compare cars when we want to choose one that is fuel-efficient.

We calculate the potential costs when we decide to rent or buy a car.

We calculate the profit and losses when buying or selling cars.

Estimate how many miles can you drive if you change the tires (front <-> back) at the best moment. Rear tires of your car wear out after 60,000 miles, while the front tires wear out twice faster.

We accept or refuse bids when selling cars.

In the last case, you don’t need to know the complex optimal choice theory and its formulae. It’s enough just to keep in mind several simple rules that help you to make wise decisions. People who spend a few minutes on simple calculations always enjoy their choice.

December 9, 2012 1 Comment

When required to make a decision, I have the option to produce simple calculations, guess, or even refuse to decide. What is better?

The answer depends on many circumstances, including:

- Complexity of the challenge.
- Usefulness of the conclusion.
- Individual ability / habits to analyze challenges.
- Time available.

I meet difficult challenges very often. What technique should I use? Should I work it out or should I guess?

Calculations are beneficial in terms of time and money in the following examples:

I am ready to spend my time on simple analysis and calculation in such cases.

Weinstein and Adam [1] advise **guesstimating** certain categories of challenges. A guesstimate is an informal English contraction of guess and estimate and is used to describe an estimate made without complete information. Another term for this is an educated guess at something for which no better information will become available.

There are a group of challenges called “Fermi problems” (after the great nuclear physicist) that will be accurate to within an order of magnitude. A mistake of up to 10 times is acceptable. The examples are:

- How many people will potentially buy a new car next year in a city?
- How many gas stations between Boston and New York?
- How many people will come to buy my car if I advertize on the Internet?
- How many tennis balls can fit in a school bus?
- What score does John expect to receive on the exam?
- How long is Anna’s hair?
- How many times heavier than a rabbit is an elephant?
- How many customers visit a shop everyday?

I need to guesstimate in order to answer such questions.

The answer to the question in the title “Calculate or Guess?” is yes. I calculate when I have time and the ability, I guesstimate when a conclusion with order of magnitude is acceptable, and I trust my gut feeling in all other cases.

*1. *Lawrence Weinstein and John A. Adam,* Guesstimation: Solving the World’s Problems on the Back of a Cocktail Napkin. *2008 Princeton University Press. ISBN 9780691129495