Question

On January 21 of this year, the first law requiring that drivers of automobiles have licenses went into effect. To learn the year, solve this puzzle. The two-digit number formed by my tens and units digits is the 12th prime number and is considered normal body temperature when measured in degrees Celsius. My tens digit is 33 1/3% of my hundreds digit. The sum of all of my digits is the same as the number of triangles that make up an icosahedron. What year am I? Explain.

Answer 1

1937

Explanation:

Let the digits of the number = xyzw

(a) 1st clue

Prime numbers: 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37,…

The twelfth prime number is 37, and normal body temperature is 37 °C.

zw = 37

z = 3

w = 7

(b) 2nd Clue

z = ⅓y Multiply each side by 3

y = 3z

= 3 × 3

= 9

(c) 3rd clue

An icosahedron has 20 triangular faces.

x + y + z + w = 20

x + 9 + 3 +7 = 20

x + 19 = 20

x = 1

x = 1; y = 9; z = 3; w = 7

xyzw = 1937