3.
250 million = 250,000,000. There are 9 digits in this number.
1128
25 buhgillion
453 0-9 9 digits 10-99 180 digits 100-250 453 digits
9 digits used for pages 1 to 9 (9 pages * 1 digit)180 digits used for pages 10 to 99 (90 pages * 2 digits)453 digits used for pages 100 to 250 (151 pages * 3 digits)Total = 9 + 180 + 453 = 642 digits used.(Of course a trick answer is 10 as there are only 10 possible different digits in decimal).
642
There are 2.54 cm per inch and 12 inches per foot. Therefore, there are 30.48 cm/foot, and 250 cm = 250/30.48 = 8.20 feet, to the justified number of significant digits.
When multiplying numbers with different numbers of significant digits, the result should have the same number of significant digits as the least precise measurement. Count the number of significant digits in each number, perform the multiplication as usual, and then round the result to the least number of significant digits used in the calculation.
6 digits
6
12 digits.12 digits.12 digits.12 digits.
A quadrillion has 16 digits.