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 ~
there are 27 blue,12 yellow and 42 black marbles in a box.Jack close his eyes and draw a marble from the box.at least how many marble must be put out ensure that there are six ball of the same colour
All the primary 3 students at Royal Elementary School subcribe to at least one magazine.
150 students subscribe to Wildlife.
208 students subscribe to A - Star Maths.
88 students subscribe to both magazines
How many Primary 3 students are there at the Royal Elementary School?
tks!
There are 48 students in a class. The ratio of the number of the girl students to the number of boy students is 1: 3. How many girl students are there in the class?
Answer: There are...... girl students.
There are 48 students in a class. The ratio of the number of the girl students to the number of boy students is 1: 3. How many girl students are there in the class?
Question 5:
The ratio of boys to girls at a school is 5:4. If there are 255 boys at the school then how many students are there at the school?
Answer: students.
In a PE room, a basket contains some red, orange, yellow and green bean bags. How many students must the PE teacher send so that at least 2 students will draw 3 bags of the same colour combination? Each student is allowed to draw 3 bean bags
There are 3 grey socks, 3 blue socks and 3 yellow socks in a drawer. How many socks must Alan take out from the drawer in a dark room before there is a pair of socks of the same colour?