A license plate of a car is issued in turn from 1.
As there are many people who don't like a number of 4 in Japan, a license plate of the number including 4 isn't issued.
Which person is the person who receives a license plate of 1999 in this case?
Answer
1457th
Solution
Make a table as shown below corresponding number of each figure of a license plate to nonary system.
Answer
1457th
Solution
Make a table as shown below corresponding number of each figure of a license plate to nonary system.
License plate 1999 is 1888 of a nonary system according to the table above.
When this is changed into the decimal system, (9 × 9 × 9) × 1+ (9 × 9) × 8 + 9 × 8 + 1 × 8 = 1457.
Another solution
Because when 2000 of a nonary system is expressed in the decimal system, it is (9 × 9 × 9) × 2 = 1458, 1999 is 1458 - 1 = 1457.
