Category 3 - Number Theory
Meet #3 - January, 2000

1. The average person breathes about 20,000 times each day. If the average person lives 70 years, then how many breaths does the average person take in a lifetime? Express your answer in scientific notation. (Use 365 days = 1 year.)

    

2. Express the base 10 numeral 73 as a base 4 numeral. In other words,
   73_{base 10} = _________ _{base 4}

    

3. The diameter of a grain of sand is 0.000031 of a centimeter. If grains of sand are placed in a straight line, touching each other, then how many grains of sand are required to measure the length of a corridor (hallway) which is 1240 meters long? Express your answer in scientific notation. (Note: 100 centimeters = 1 meter.)

    

ANSWERS 1) __________ 2) __________ 3) __________