How many two-digit numbers can we make using the same digit repeated?
99 numbers can be constructed, with one or two digits, between 1 and 99, but 9 of them have one digit. Therefore, the total number of two-digit numbers that can be constructed is 99–9 = 90. Nine of those numbers have repetitions, so that my answer is 90–9 = 81.
How many four codes can be formed using digits 0 9?
10,000 possible combinations
There are 10,000 possible combinations that the digits 0-9 can be arranged into to form a four-digit code. Berry analyzed those to find which are the least and most predictable.
How many different ways can you write a 4 digit number?
For each choice of the first two digits you have 10 choices for the third digit. Thus you have 10x10x10 = 1000 choices for the first three digits. Finally you have 10 choices for the fourth digit and thus there are 10x10x10x10 = 10 000 possible 4 digit combinations from 0-9.
How many 2-digit numbers are there in 5*9?
(a) If repetition is allowed, we have 5 choices for the units digit (any of the 5 even digits); then we have 9 choices for the tens digit (any digit except 0). That makes 5*9 = 45 2-digit numbers. (b) If repetition is not allowed, then there are two cases to consider.
What is the total number of possible 2-digit even numbers?
Of the 10 digits, 5 are even. So in both cases there are 5 choices for the units digit of the 2-digit number. (a) If repetition is allowed, then there are 10-1 = 9 choices for the tens digit. (9 because you can not use zero as the “tens” digit). The total number of possible 2-digit even numbers is 9*5 = 45, if repetition is allowed .
What is the value of 5^4 without repetition?
Each of the four digits can have 5 possible values. 5^4 = 625. 3. “without repetition” means both of the above cases. Then the others who answered 120 are correct. The first digit can be one of the five { 1, 2, 3, 4, 5 }, the
How many possibilities are there to fill the first digit?
1st digit can be filled by any of the 6 numbers. Similarly 2nd, 3rd and 4th digits. Hence each digit will have 6 possibilities. Now the first digit can be filled by any of the six numbers. Therefore there are 6 possibilities Two answers are possible.