EXPERT QUIZ

CELEBRATEPI DAY

1. Which of the following binary numbers is closest in value to pi:a. 11.0010010000111111b. 101.110101000111100c. 10.0001101010110100d. 1.10111011010010011e. 111.010111101011111

2. The probability that two integers pulled out at random arecoprime is?a. π2/6 b. π2/12 c. 6/π2 d. 3/π2

3. Imagine you wrapped a rope tightly around the Earth at theequator. How much longer would you have to make the rope ifyou wanted it to be exactly 1 foot above the Earth’s surface allthe way around?a. 2π feetb. 2πr feet, where r is the radius of the Earthc. πr2

4. Among the digits of pi currently known, the concentration ofeach of the digits (0–9) are close to equal. However, in the first30 places of pi’s decimal expansion, which digit is completelymissing?a. 7 b. 0 c. 2 d. 8

5. I’m thinking of a 10-digit integer whose digits are all distinct.It happens that the number formed by the first n of them isdivisible by n for each n from 1 to 10. What is my number?

www.raytheon.com/piday

© 2017, Raytheon Company. All rights reserved. GBS Advanced Media-East 4434859 (3/2017)

QUIZ – CONTINUED

6. Circle A is one mile wide. Circle B is two miles wide. Which of the following statements is true? a. Circle B has twice the area of Circle A b. Circle B’s area is four times greater than that of Circle A c. Circle B’s area is equal to Circle A’s area d. Circle B is eight times larger than Circle A

7. A Mars rover has been driving on the Red Planet for 11 years and is now approaching a marathon distance of 42.195 kilometers. When the rover reaches the marathon mark, how many times will its 25-centimeter diameter wheels have rotated?

8. If one were to find the circumference of a circle the size of the known universe, requiring that the circumference be accurate to within the radius of one proton, how many decimal places of pi would need to be used? a. 2,000,000 b. 300 c. 48,000 d. 39

9. In what year were the first 100 digits of pi calculated? a. 48 B.C. b. 1947 c. 1701 d. 1812

10. In 1949, a digital computer was first used to calculate pi. To how many decimal places was this computer, ENIAC (Electronic Numerical Integrator and Computer), able to find pi (it took 70 hours)? a. 10,493 b. 576 c. 2037 d. 8331 e. 297,454

QUIZ ANSWERS

1. Which of the following binary numbers is closest in value to pi: a. 11.0010010000111111

2. The probability that two integers pulled out at random are coprime is? c. 6/π2

3. Imagine you wrapped a rope tightly around the Earth at the equator. How much longer would you have to make the rope if you wanted it to be exactly 1 foot above the Earth’s surface all the way around? a. 2π feet

4. Among the digits of pi currently know, the concentration of each of the digits (0–9) are close to equal. However, in the first 30 places of pi’s decimal expansion, which digit is completely missing? b. 0

5. I’m thinking of a 10-digit integer whose digits are all distinct. It happens that the number formed by the first n of them is divisible by n for each n from 1 to 10. What is my number? Answer: 3,816,547,290

6. Circle A is one mile wide. Circle B is two miles wide. Which of the following statements is true? b. Circle B’s area is four times greater than that of Circle A

7. A Mars rover has been driving on the Red Planet for 11 years and is now approaching a marathon distance of 42.195 kilometers. When the rover reaches the marathon mark, how many times will its 25-centimeter diameter wheels have rotated? Answer: 53,724.3 rotations

QUIZ ANSWERS – CONTINUED

8. If one were to find the circumference of a circle the size of the known universe, requiring that the circumference be accurate to within the radius of one proton, how many decimal places of pi would need to be used? d. 39

9. In what year were the first 100 digits of pi calculated? c. 1701

10. In 1949, a digital computer was first used to calculate pi. To how many decimal places was this computer, ENIAC (Electronic Numerical Integrator and Computer), able to find pi (it took 70 hours)? c. 2037