Exercise 7. Choose 2 numbers, without repetition, from 0, 3, 5, 6, 9 to form a 2-digit number. How many numbers with a digit “9” are there?
A. 6 B. 9 C. 7 D. 8
Choose 3 digits, without repetition, from 1, 2, 4, 6, 8 to form 3-digit even numbers. How many numbers are there ?
Please help me !
bạn ghi là 124 nhé
Choose 3 digits from 8, 6, 0, 5, 2 and 1 to form 3-digit numbers. How many odd numbers
are there? (The repetition of digits is not allowed)giúp me với
Choose 3 digits, without repetition, from 2, 3, 4, 5, 6 to form 3 – digit numbers. How many odd numbers (s) is/are there?
The Partial Permutations of N items taken K at a time is:
N! / (N - K)!
For N = 9 and K = 3, we get
9! / 6! = 7*8*9 = 504 possible three digit numbers.
Of those, odd are those which end in 1,3,5,7,9 (5 accepted endings) from a total of 1,2,3,4,5,6,7,8,9 (9 possible endings).
So, we take 5/9 of 504.
(5/9)*504 = 280.
choose 3 digits from 1, 3, 4, 5, 9 to form 3-digit numbers. how many number(s) that can be divisible by 5 is / are there?
choose 3 digits from 1, 3, 4, 5, 9 to form 3-digit numbers. how many number(s) that can be divisible by 5 is / are there?
A,B,C,D,A+C,B+C,A+D,B+D represent 8 diffirent natural numbers from 1 to 8. If A is the largest number in the number from 1 to 8.Find A
How many natural numbers are there between 100 and 999 that unit-digit and tens-digit equal hundreds-digit ?
Combinatorics
21. 15 students join a competition. Only top 5 students can be promoted to next round. How many different way(s) of promotion advance is / are there?
Different way: Cách khác nhau.
22. It is known that there are 8 classes of grade 5 in a primary school. At least how many students are there in grade 5 to ensure there exist 41 students in the same class?
At least: Ít nhất; Ensure: Chắc chắn; Exist: Tồn tại.
23. Choose 3 digits from 1, 2, 3, 4, 6, 8 and 0 to form 3-digit numbers. How many even number(s) greater than 300 is / are there? (The repetition of digits is not allowed)
Digit: Chữ số; 3-digit number: Số có 3 chữ số; Even number: Số chẵn; Greater than: Lớn hơn; Repetition of digits is not allowed: Các chữ số không được lặp lại.
24. A flight of stairs has 10 steps. Peter can go up for 1 step, 2 steps or 3 steps each time. How many way(s) is / are there for Peter to go up the stairs?
Step: Bước; Way: Cách.
25. Numbers are drawn from 80 integers 20 to 99. At least how many number(s) is / are drawn at random to ensure that there are two numbers whose sum is 85?
Integer: Số nguyên; At least: Ít nhất; Random: Ngẫu nhiên; Ensure: Chắc chắn; Sum: Tổng.
~ End of Paper ~
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Đọc cái bài mà mún trầm kẻm!
Combinatorics
21. 15 students join a competition. Only top 5 students can be promoted to next round. How many different way(s) of promotion advance is / are there?
Different way: Cách khác nhau.
22. It is known that there are 8 classes of grade 5 in a primary school. At least how many students are there in grade 5 to ensure there exist 41 students in the same class?
At least: Ít nhất; Ensure: Chắc chắn; Exist: Tồn tại.
23. Choose 3 digits from 1, 2, 3, 4, 6, 8 and 0 to form 3-digit numbers. How many even number(s) greater than 300 is / are there? (The repetition of digits is not allowed)
Digit: Chữ số; 3-digit number: Số có 3 chữ số; Even number: Số chẵn; Greater than: Lớn hơn; Repetition of digits is not allowed: Các chữ số không được lặp lại.
24. A flight of stairs has 10 steps. Peter can go up for 1 step, 2 steps or 3 steps each time. How many way(s) is / are there for Peter to go up the stairs?
Step: Bước; Way: Cách.
25. Numbers are drawn from 80 integers 20 to 99. At least how many number(s) is / are drawn at random to ensure that there are two numbers whose sum is 85?
Integer: Số nguyên; At least: Ít nhất; Random: Ngẫu nhiên; Ensure: Chắc chắn; Sum: Tổng.
~ End of Paper ~
Combinatorics
21. 15 students join a competition. Only top 5 students can be promoted to next round. How many different way(s) of promotion advance is / are there?
Different way: Cách khác nhau.
22. It is known that there are 8 classes of grade 5 in a primary school. At least how many students are there in grade 5 to ensure there exist 41 students in the same class?
At least: Ít nhất; Ensure: Chắc chắn; Exist: Tồn tại.
23. Choose 3 digits from 1, 2, 3, 4, 6, 8 and 0 to form 3-digit numbers. How many even number(s) greater than 300 is / are there? (The repetition of digits is not allowed)
Digit: Chữ số; 3-digit number: Số có 3 chữ số; Even number: Số chẵn; Greater than: Lớn hơn; Repetition of digits is not allowed: Các chữ số không được lặp lại.
24. A flight of stairs has 10 steps. Peter can go up for 1 step, 2 steps or 3 steps each time. How many way(s) is / are there for Peter to go up the stairs?
Step: Bước; Way: Cách.
25. Numbers are drawn from 80 integers 20 to 99. At least how many number(s) is / are drawn at random to ensure that there are two numbers whose sum is 85?
Integer: Số nguyên; At least: Ít nhất; Random: Ngẫu nhiên; Ensure: Chắc chắn; Sum: Tổng.
~ End of Paper ~
how many distinct 4 digit numbers are divisible by 2 can be from digits 0, 2, 5, 6, 9