Using only positive digits, and disregarding their order, 3 ways.
9
one digit: 5 ways two digits: 5 * 9 ways three digits: 5 * 9 * 8 ways four digits: 5 * 9 * 8 * 7 ways ... ten digits: 5 * 9! ways So if you have to use ten digits, then the answer is 5 * 9! = 1814400. If you can use anywhere from one to ten digits, then the answer is: 5 * (9! + 8! + 7! + 6! + 5! + 4! + 3! + 2! + 1) = 2045565
192 ways
Three.
NEGATIVE 83
There are 676,000 ways to make the license plates.
i guess the answer is 54. A group of three digits can be selected from the 5 digits in 9 ways and each group can be arranged in 3! (i.e., 6) ways respectively and hence the answer is 6*9=54
9
one digit: 5 ways two digits: 5 * 9 ways three digits: 5 * 9 * 8 ways four digits: 5 * 9 * 8 * 7 ways ... ten digits: 5 * 9! ways So if you have to use ten digits, then the answer is 5 * 9! = 1814400. If you can use anywhere from one to ten digits, then the answer is: 5 * (9! + 8! + 7! + 6! + 5! + 4! + 3! + 2! + 1) = 2045565
192 ways
Three.
One example! 4 × 5 × 6 × 7 − 9 = 831 -------- I disagree with this answer. Three digits can be chosen from five in 5C3 = 10 ways For each of these choices the three digits can be ordered in 6 ways. Therefore, 10(6) = 60 numbers can be formed.
The number of strings of four decimal digits that have exactly three digits which are nine is the number of ways to choose three places to choose the nines multiplied by the number of possibilities for the other digits (because you can put all of the possibilities in an array so that each column has a different way of arranging the nines and that each row has a different set of other digits (because they do not affect each other)). The number of ways to choose the three places to choose the nines is the same as the number of ways of choosing 4-3=1 spot for there not to be a nine. The number of ways of choosing 1 spot where there are 4 spots is 4 (the first, the second, the third, or the fourth). Since there are 9 digits that are not nine, the number of choices for the other digits is 9 (since there is only one digit). Thus, there are 4*9=36 strings of four decimal digits that have exactly three digits which are nine.
NEGATIVE 83
Three ways.
Three different ways.
Numbers formed should be of at least 3 digits means they may be of 3 digits, 4 digits, 5 digits or 6 digits. There are 6 choices for digit in the units place. There are 5 and 4 choices for digits in ten and hundred’s place respectively. So, total number of ways by which 3 digits numbers can be formed = 6.5.4 = 120 Similarly, the total no.of ways by which 4 digits numbers can be formed = 6.5.4.3 = 360. the total no. of ways by which 5 digits numbers can be formed = 6.5.4.3.2 = 720. The total no.of ways by which 4 digits numbers can be formed = 6.5.4.3.2.1 = 720. So, total no.of ways by which the numbers of at least 3 digits can be formed = 120 + 360 + 720 + 720 = 1920.