Operational Mathematics Interview Questions & Answers:

1. Rounded off to the nearest whole year, how many years would it take for your money to double in an investment that was increasing with an annual compound rate of 3.5%?

20 years

2. In statistics, what is the common term for the square root of the variance?

standard deviation

3. What is the greatest common divisor for the numbers 102 and 30?

6

4. What is the mean for the following data set of 5 numbers:

84, 50, 73, 27, 16

Answer: 50

5. What is the sum of the internal angles of a pentagon:

540°

6. If perfect numbers, except 6, can be expressed by the sum of the cubes of an unbroken sequence of consecutive odd integers, what are the consecutive odd integers which, when cubed, give the perfect number 28?

13 + 33

7. What is the cube root of 729?

9

8. How many degrees are there in o radians:

180o

9. If you start with 1 bacterium and double the number every 15 minutes, how many bacteria will you have at the end of 3 hours and 45 minutes?

32,768

10. According to Set Theory, sets that do NOT contain themselves are typically referred to as:

normal sets

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11. If the length of the cycloid is 4 times the diameter of a rotating circle, then the area under the arch traced out by that cycloid is how many times the area of the rotating circle?

3 times

12. What form of geometry is one in which the parallel postulate of Euclidean Geometry does NOT hold:

non-euclidean geometry

13. A farmer wishes to make a straight barbed wire fence 80 feet long. He wants to have a fence post every 8 feet. How many fence posts does he need?

11

14. What is the square root of 256?

16

15. The product of 6 factorial is how many times larger than the product of 5 factorial?

6

16. Where is the y intercept for y = sin x?

zero

17. In 1700 AD, this person showed that a series of 0s and 1s could be used to denote a number:

Gottfried Liebniz

18. Every even integer greater than 2 can be written as the sum of two primes. Give the respective two pairs of prime numbers that when added give 8 and 12:

5 and 3 for the number 8; and 7 and 5 for the number 12

19. What 3 consecutive numbers add up to 45?

14, 15, and 16

20. The imaginary unit i is numerically defined as what?

-1

21. Farmer John grows corn, tomatoes, potatoes and squash. He has only 2 fields for growing these products and cannot grow more than one product per field. How many planting combinations can be done in one season?

10

22. The converse of this theorem is: if the sum of the squares of two sides of a triangle equal the square of the third side then the triangle is a right triangle. What is the name of the theorem?

Pythagorean Theorem

23. Six factorial equals what number?

720

24. What is the total angular distance in degrees over a sphere?

360 Degrees

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25. Give the rational numbers in the following set:

-8, - 3 , 1/5, 0, π

Answer: -8, 1/5, 0

26. A country adopted a policy requiring all couples to continue having children until they had a girl, after which they must stop having children. How many children will the average family have and what will the sex distribution be?

Two Children - One Boy And One Girl

27. When a quadratic function is plotted on a typical graph, it assumes what shape?

Parabola

28. If in a sequence of natural numbers, starting with 2, you begin eliminating every second number after 2, then every third number after 3, then every fourth number after 4, and so on, what type of numbers will be left?

prime numbers

29. Convert 3/20 into a percentage:

15%

30. n radians encompass what percent of a circle?

50%

31. Give the range for the following six values 2, 7, 11, 19, 25, 33:

31

32. Using an x- y coordinate axis, a parabola is represented by the equation x2 = 6y. The vertex of this parabola is at what coordinate point:

1. (0, 0)
2. (1, 1)
3. (1, 2)
4. (2, 2)

Answer: A

33. In the hexadecimal counting system, the letter c stands for what base-10 number:

1. 12
2. 3
3. 16
4. 11

Answer: A

34. Which of the following is the surface area of a perfect sphere with a radius of 10 meters?

1. 1256.7 m2
2. 1200.5 m2
3. 628 m2
4. 125.7 m2

Answer: A

35. The Babylonian number system is base 60, which makes it:

1. vigesimal
2. quinary
3. binary
4. sexagesimal

Answer: D