K
Khách

Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.

30 tháng 6

 Dịch đề: Cho dãy số 2, 7, 12, 17, 22, 27,..., 302, 307. Tìm chữ sồ hàng đơn vị của tích tất cả các số trong dãy.

 Solution (in English):

 In the sequence, there are \(\left(302-2\right):10+1=31\) numbers that end with 2 and \(\left(307-7\right):10+1=31\) numbers that end with 7.

 Therefore, the unit digit of the product is also the unit digit of:

 \(A=2\times2\times2\times...\times2\times7\times7\times7\times...\times7\)

          (31 numbers 2)       (31 numbers 7)

 We have to find out what is the final digit of \(2\times2\times...\times2\)  (31 times) and \(7\times7\times...\times7\) (31 times)

 Consider the number \(N=2\times2\times...\times2\) (\(n\) times)

 If \(n=1\), then \(N=2\)

 If \(n=2\), then \(N=4\)

 If \(n=3\), then \(N=8\)

 If \(n=4\), then \(N=16\rightarrow\) the last digit is 6

 If \(n=5\), then \(N=32\rightarrow\) the last digit is 2

 If \(n=6\), then \(N=64\rightarrow\) the last digit is 4

 If \(n=7\), then \(N=128\rightarrow\) the last digit is 8.

 If \(n=8\), then \(N=256\rightarrow\) the last digit is 6.

...

 From here we can see a pattern: If \(n\) has a remainder of 3 when being divided by 4, the last digit of N is 8. Thus, the final digit of \(2\times2\times...\times2\) (31 times) is 8 since 31 has a remainder of 3 when being divided by 4.

 Using the same method of reasoning, we can deduce that \(7\times7\times...\times7\) (31 times) ends with 3.

 Therefore, the final digit of A must be the final digit of \(8\times3=24\), which is 4.

 So the answer is 4.

 

4
456
CTVHS
30 tháng 6

The number of terms in the above squence is:

\(\left(307-2\right):5+1=62\) (terms)

The total number squence above is:

\(\left(307+2\right)\times62:2=9579\)

So....

21 tháng 1

trả lời nhanh cho mình nhé

 

29 tháng 1

vao goolgle tra

15 tháng 7 2019

The ones digit: 9

The tens digit: 2

The hundreds digit: 1

The thousands digit: 3

Answer: 3129

9 tháng 2

là 3129

2 tháng 4 2018

123456789

2 tháng 4 2018

ko hieu

2 tháng 10 2021

Let the tens digit be x.

=> The ones digit will be x - 2.

The hundreds digit will be 2x.

The sum of all three digits: x + x - 2 + 2x = 14 

=> x = 4

 

The number is: 842.

 

2 tháng 10 2021

Chữ số hàng chục của số có 3 chữ số hơn chữ số hàng đơn vị là 2. Chữ số hàng trăm gấp đôi chữ số hàng chục. Nếu tổng của tất cả các chữ số là 14. Số là gì?

 

Gọi chữ số hàng chục là x.

=> Chữ số hàng đơn vị sẽ là x - 2.

Chữ số hàng trăm sẽ là 2x.

Tổng của cả ba chữ số: x + x - 2 + 2x = 14

=> x = 4

 

Số cần tìm là: 842.

trả lời bài này cho mình vớiCâu 1 How many double digit numbers are there?Answer: numbers. Câu 2 How many single digit numbers are there?Answer: numbers. Câu 3 Write the words in number form which consist of: 7 hundred thousands, 6 thousands, 3 hundreds, 4 tens and 2 units.Answer:  Câu 4 Fill in the sequence with the missing number in order to have 3 consecutive natural numbers.99; 100;  Câu 5 1kg of apple costs 2 dollar and 1kg of orange costs 3 dollar more than an apple. Jean bought...
Đọc tiếp

trả lời bài này cho mình với

  • Câu 1

     

    How many double digit numbers are there?
    Answer:

     

    numbers.

     

  • Câu 2

     

    How many single digit numbers are there?
    Answer:

     

    numbers.

     

  • Câu 3

     

    Write the words in number form which consist of: 7 hundred thousands, 6 thousands, 3 hundreds, 4 tens and 2 units.
    Answer:

     

     

  • Câu 4

     

    Fill in the sequence with the missing number in order to have 3 consecutive natural numbers.
    99; 100;

     

     

  • Câu 5

     

    1kg of apple costs 2 dollar and 1kg of orange costs 3 dollar more than an apple. Jean bought 10kg of apples and 8kg of oranges. How much did she have to pay for the fruits?
    Answer:

     

    dollar.

     

  • Câu 6

     

    The perimeter of a square garden is 36m. What is its area?
    Answer: Its area is

     

    m^2m2.

     

  • Câu 7

     

    Find the product of 7 tens and 7 ones.
    Answer:

     

     

  • Câu 8

     

    Anna has 206 stickers and Mary has 78 stickers. How many stickers must Anna give to Mary so that they have the same number of stickers?
    Answer:

     

    stickers.

     

  • Câu 9

     

    The product of 40 and a number m, is a 2-digit number that greater than 40. The value of m is

     

     

  • Câu 10

     

    A number has a digit 3 in ones place. It is greater than 64 but less than 82. What number is it?
    Answer:

     

     

2
29 tháng 3 2018

Câu 3: 

Answer:

700.000 + 6000 + 300 + 40 + 2 = 706342.

Câu 5: 

Answer:

Cost to buy apples and buy oranges are:

         (10 x 2) + (8 x 3) = 44 (dollar)

                                     Answer: 44 dollar

Câu 6:

Answer:

The following squares are:

       36 : 4 = 9 (cm)

Square area is:

       9 x 9 = 81 (cm2)

                Answer: 81 cm2

Câu 8:

Answer:

Anna than Mary ket number is:

         208 - 78 = 128 (kets)

So: Anna must give Mary the same number as:

        128 : 2 = 64 (kets)

                    Answer: 64 kets

19 tháng 3 2019

câu 4 là 101 vì số kế tiếp của nó là số có 3 chữ số

12 tháng 1 2022

C

1. Multiple Choice Questions (3 points each)1. What is the answer to 4 × 4 + 4 + 4 + 4 + 4 + 4 × 4 + 4 + 4 + 4 ?3248601001442. Helen wrote a one-digit number and then wrote an additional digit to its right. She added 19 to the obtained number and got 72. What number did Helen write first?235673. Jack wishes to write different numbers from 1 to 9 in the cells of the table so that the total of the three numbers of each row and each column were equal to 15. Some of the numbers are already...
Đọc tiếp

1. Multiple Choice Questions (3 points each)
1. What is the answer to 4 × 4 + 4 + 4 + 4 + 4 + 4 × 4 + 4 + 4 + 4 ?
32
48
60
100
144
2. Helen wrote a one-digit number and then wrote an additional digit to its right. She added 19 to the obtained number and got 72. What number did Helen write first?
2
3
5
6
7
3. Jack wishes to write different numbers from 1 to 9 in the cells of the table so that the total of the three numbers of each row and each column were equal to 15. Some of the numbers are already written there. What number must be written in place of the question mark?
Hình ảnh không có chú thích
1
2
3
4
5
4. Each friend: Mary, Elly, Paul, and Mike has exactly one of the following animals: a cat, a dog, a gold fish, and a parrot. Elly has a pet with fur. Mike has a pet with four legs. Paul has a bird, and Mary and Elly don't like cats. Which of the following sentences is not true?
Mike has a dog
Paul has a parrot
Mary has a golden fish
Mike has a cat
Elly has a dog
5. Elise had a sum of money. She gave half of it away to her brother. Then she used half of the remainder to buy a new comic book. Next she gave half of what was left to her older sister. Finally, she found that she had $7 dollars remaining. How much money did she have at first?
30
46
56
65
None of the above
6. Peter has a total of 100 chickens and rabbits on his farm. If the animals have 260 legs altogether, how many chickens are there on the farm?
30
40
50
60
70
7. There are 14 children at a party. If each child shakes hands with each other exactly once, how many handshakes will take place?
75
85
90
91
93
8. The area of the figure in the picture below is equal to:
Hình ảnh không có chú thích
30
38
44
60
None of the above
9. The weight of 3 apples and 2 oranges is 255 g. The weight of 2 apples and 3 oranges is 285 g. Each apple weighs the same and each orange weighs the same. What is the combined weight of 1 apple and 1 orange?
110 g
108 g
105 g
104 g
102 g
10. There were 25 questions in a mathematics quiz. If a question was answered correctly, 4 marks would be given, otherwise 1 marks would be deducted. If John scored 85 marks in the mathematics quiz, how many questions had he answered correctly?
20
21
22
23
24
11. Carl is four times as old as Pam, who is one third as old as Jackie. If Jackie is 18, what is the sum of their ages?
64
54
48
24
18
12. Five cities all got more rain than usual this year. The five cities are: Last Stand, Mile City, New Town, Olliopolis, and Polberg. The cities are located in five different areas of the country: the mountains, the forest, the coast, the desert, and in a valley. The rainfall amounts were: 12 inches, 27 inches, 32 inches, 44 inches, and 65 inches.* The city in the desert got the least rain; the city in the forest got the most rain.* New Town is in the mountains.* Last Stand got more rain than Olliopolis.* Mile City got more rain than Polberg, but less rain than New Town.* Olliopolis got 44 inches of rain.* The city in the mountains got 32 inches of rain; the city on the coast got 27 inches of rain. Which city is in the desert ?
Mile City
Polberg
New Town
Last Stand
Olliopolis
13. If you count 21 letters in the English alphabet from the end and 20 letters from the beginning , which letter will exactly appear in the middle of the sequence thus formed?
K
L
M
N
O
14. A, B, C, D, E, F, G, H and I are nine houses. C is 2km East of B. A is 1km North of B and H is 2km South of A. G is 1km West of H while D is 3km East of G. F is 2km North of G, I is situated just in the middle of B and C, while E is just in the middle of H and D. Find the distance between E and G.
1.5 km
2 km
3 km
4 km
None of the above
15. There is an 8-sided dice whose faces each have one different number from the set {1, 2, 3, 4, 5, 6, 7, 8}. The numbers on opposite faces always have a sum of 9. The dice is rolled twice and the two values appearing on top are multiplied. How many ways are there that this product is divisible by 9?
1
2
3
4
5

4
10 tháng 10 2021

giúp mình với!

11 tháng 10 2021

hic, cái này là kiến thức lớp 5 mà huhuhu 

9 tháng 2 2018

A=90

k cho mình nha

7 tháng 2 2018

Nếu A chia cho 9 thì tổng của giá trị và 9 là số lớn nhất 2 chữ số. Tìm giá trị của A. Trả lời: A =

13 tháng 6 2020

I don`t no 

:<

16 tháng 6 2020

ko bk làgm

11 tháng 4 2018

chịch ok

12 tháng 4 2018
chán thế