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?
1. A machine P can print one lakh books in 8 hours, machine Q can print the same number ò books in 10 hours while machine R can print them in 12 hours. All the machines are started at 9 A.M. While machine P is closed at 11 A.M . And the remaining two machines complete work (to print one lakh books) be finish?
2.A can lay railway track between two given stations in 16 days and B can do the same job in 12 days. With help of C, they did the job in 4 days. Then, C alone can do the job in
10 children are at the judo club their teacher has 80 sweets if he gives each girl same amount of sweets there are three sweets leftover how many boys are at the club
ai giỏi tiếng anh giúp mình với
In order to make a call between two cities, custumer have to pay $0.4/ minute if call is made between 6:00 am to 24:pm, and $0.25 if the call is made from 24:00 to 6:00 in the morning
According to a notice, if the call between two cities at 2:00 cost $16 then how much do they have to pay for the call of the same duration at 10:00 pm
(You have to write down the calculations and result, but don't have to write down any explanation)
Each morning, Catherine walks to school. At one- fourth of the way she passes the machine, a tractor station; at one-third of the way, the railroad station. At the machine and tractor station its clock shows 7 : 30, and at the railroad station its clock shows 7:35, When does she leave her house, when does she reach school ?
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 ~
One loaf bread and six rolls cost $1.80. At the same prices, two loaves of bread and four rolls cost $2.40. How much does one loaf of bread cost.
Question 3. Two neon lights are turned on at the same time. One blinks every 4 seconds and the other blinks every 6 seconds. Answer the following questions, give your answer only.
a) How long will it take them to blink simultaneously for the first time after they are turned on? (simultaneously: at the same time)
b) How many times will they blink simultaneously in the first 70 seconds after they are turned on?