Question 2. A staircase has 26 steps. Tung and Bao count the steps; one from the bottom to the top and the other from the top to the bottom. They meet at one step which Tung indicates as the 12th.
a)
How many steps did Tung count?
Question 8. A staircase has 26 steps. Tung and Bao count the steps; one from the bottom to the top and the other from the top to the bottom. They meet at one step which Tung indicates as the 12th. At which number does Bao indicate this step?
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 ~
Alex has a great collection of badges that he wants to count. He knows that he has between 120 and 150, but not the exact number. He decides to count them in fives, and he has 2 left over. He then counts them in sixes and he has 3 left over. Can you work out exactly how many badges Alex has?
Question 1: What is 1/6 of 744? Answer: 124
Question 2: Express seventy thousand, four hundred and nine in numerals. Answer: 70409
Question 3: Study the pattern. 88:8=11 880:8=110 8800:8= ? The missing number is 1100
Question 4: Subtract 346 from 752. Answer: 406
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: 459 students.
Question 6: The product of 2 different natural numbers is 9. Their sum is 10
Question 7: Jack, Mary and Jacob buy ice creams. Jack buys twice as many as Mary. Jacob buys three times as many as Jack. If Jacob buys 12 ice creams then Mary buys 2 ice creams.
Question 8: My giant flower doubles its size every day. On Friday, it is 5 ( hay 10 gì đó ) times as big as its was on the preceding Sunday.
Question 9: If we write all of the whole numbers from 10 through 99 and cross out any number in which the first or second digit is divisible by 2 (for example, 41 is crossed out as 4 is divisible by 2 and 36 is crossed out as 6 is divisible by 2), how many numbers are crossed out? Answer: 65 numbers.
Question 10: It takes Bella three hours to clean a house. It takes Anna two hours to clean the house. How long would it take for them to clean it together? Answer: 72 minutes.
Question 1 :
My giant flower doubles its size every day. On Friday, it is...... times as big as its was on the preceding Sunday.
Question 2:
100 hundreds + 1000 tens = .... ones
Question 7:
A set of five different numbers has an average of 12. If the average of four smallest numbers is 10 then the greatest number is .......
Question 8:
Jack, Mary and Jacob buy ice creams. Jack buys twice as many as Mary. Jacob buys three times as many as Jack. If Jacob buys 12 ice creams then Mary buys...... ice creams.
Question 9:
If we write all of the whole numbers from 10 through 99 and cross out any number in which the first or second digit is divisible by 2 (for example, 41 is crossed out as 4 is divisible by 2 and 36 is crossed out as 6 is divisible by 2), how many numbers are crossed out?
Answer:...... numbers.
Question 10:
Peter and John played in fifteen rounds game. In each round, the winner scored 5 points and the loser scored 2 points. At the end of the game, John’s total score was 57 points. How many rounds did Peter win?
Answer: ...... rounds.
Ai nhanh và làm đúng được 3 tick
1: the perimeter of a circle is 15,7 dm. Its's area is...cm2
2: the ratio of the number of girls to the number of boys in a classroom is 5:4. When 10 girls left the classroom, the ratio of the number of boys to the number of girls became 4:3. How many students were in the classroom at first?
3: 47/250 dm3=...cm3
4: At the party 60% of the boys are dancing with 80% of the girls. How many people are dancing if there are 35 people ( A pair cludes only one boy and one girl)
5: An aquarium is 8dm deep, 12 dm long and 0,3 m wide. What is the volume of the aquarium in cubic centimeter?. Answer: the volume of the aquarium is...cm3
Question 1: What is the quotient of 0.51 and 17 ? Answer : ......
Question 2: The distance from Anna's house to the store is 1/2 mile . Anna run to the store twice a day , 7 days a week for 3 weeks . How many miles does she run in total ? Answer .....miles
Question 3: Jack needs to earn enough money to buy a new skateboard that costs $48.45 . He has $15.34 . How much money does he need to buy the skateboard ? Answer: $.........
both A and B province 105 km apart. motnguoi at 8 hours 15 minutes cycling from A to B at the same time a car from B to A. the two met at 9 hours 30 minutes
Asian. the velocity of each car knows the speed of each car knows the speed of the automobile velocity 5x bicycle
b. A confluence how many kilometers?
