## babybats 2 years ago Suppose that the chain could go all the way around the planet. Then the chain's length would be equal to the circumference of the earth at the equator (about 24,000 miles). Assuming that the average adult arm span is 6 feet, how many people would it take to make this human chain? A. 21,220,000 B. 20,120,100 C. 22,200,000 D. 21,120,000

1. Jerry)123gnzcraft

Here - how many feet are in a mile

2. Jerry)123gnzcraft

Here - how many feet are in a mile? (5280) Multiply that many feet times the number of miles around the earth (24000 x 5280 = 126,720,000 ft) *divide* by the 6 ft arm spans - - 126,720,000 ft / 6 ft = 21,120,000 people If it takes 20 seconds for the signal to reach the 60th person, that means it takes *1* second for every *3* people - - divide the number of people by *3* to get the number of seconds 21,120,000 / 3 = 7,040,000 seconds Now... how many seconds are in *one* hour ? (Hint : 3,600) Divide the total number os seconds by the number of seconds in an hour 7,040,000 / 3600 = 1955 1/2 hours

3. babybats

oh...thats easier then expected..thanks

4. deh_vinn