The sum of the ages of three children is 30. The oldest child is twice as old as the second oldest one. The youngest child is 10 years younger than the oldest one. Find the ages of each child.
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CV
29 tháng 7 2017
III. Em hãy đọc đoạn văn sau rồi viết T (true) cho mỗi câu đúng F (false) cho mỗi câu sai.
Even before it is born, a baby has small teeth under its gums. At about the age of six moths, its first tooth starts to grow. Before the young child is three years old, it has twenty small teeth. Between the ages of six and twelve a second set of teeth form in the gum bellow the first teeth and push them out.
.......T....... 1/ A baby has teeth under its gums even before its bith.
......F........ 2/ A baby’s first tooth appears as soon as it is born.
........F...... 3/ A three-year-old child has twenty tiny teeth.
.......T....... 4/ A child’s second set of teeth appear before it is six years old.
.......F....... 5/ A child’s second teeth begin to grow while the child still has its first teeth.
26 tháng 4 2017
Fill in each grap one suitable word to complete the passage.
Porto is the second largest city in Portuga after Lisbon. It ____IS_______ one of the major urban areas of the Iberian Peninsula. Located along the Douro river estuary in Northern Portugal, Porto is one of the oldest European centres. ______IN_____ 1996, UNESCO recognised its historic center as a World Heritage Site. Among the architectural highlights of the city, Porto Cathedral is ___THE________ oldest surviving structure. It attracts milions ______OF_____ tourists every year.
1 tháng 10 2016
Có lẽ là 17.
Lý do :
Thấy : \(22=2.11\) \(\notin P\)
\(20=2^2.5\notin P\)
\(17\in P\)
\(25=5^2\notin P\)
Do đó ....
BD
6 tháng 11 2016
. Câu hỏi :
Hỏi đứa trẻ lớn nhất hơn đứa trẻ nhỏ nhất bao nhiêu tuổi .
25 - 17 = 8 ( tuổi )
đ/s : 8 tuổi
DT
Đỗ Thanh Hải
CTVVIP
6 tháng 11 2021
III/ Choose the correct answer A, B, C or D to fill each blank in the following passage
My favourite hobby is coin (1)________. It is also one of the oldest (2)________of the world and is also called 'hobby of the Kings', as in the old times, it was only done by kings and elite class of the society. It started for me some years back when my father used to come back (3)________his foreign tours and give me coins of (4)________ countries. I started collecting them in my money box and after that I always used to wait for my new coins as much I used to wait for my father. Since then, it has become my favourite hobby. This hobby has given me information about different countries of the world. I feel extreme pleasure in (5)________my collection to (6)________. It has also taught me this lesson that A LIFE (7)________ A HOBBY IS JUST (8)________FOOD WITHOUT SALT.
1. A. collecting B. collection C. collected D. collectors
2. A. hobby B. hobbies C. game D. games
3. A. after B. in C. from D. of
4. A. other B. different C. unlike D. diverse
5. A. showing B. show C. shown D. to show
6. A. other B. another C. others D. person
7. A. with B. about C. without D. of
8. A. as B. like C. if D. likes
IV/ Choose the correct answers A, B, C or D
1.Nowadays people ________________ hours sitting in front of computers.
A.spend
B. last
C. set
D. take
2. There are many ____________ why it is important to have a hobby.
A.answers
B. reasons
C. details
D. facts
3. My sister is very keen on swimming, and she goes swimming three_________a week.
A.time
B. a time
C. times
D. timings
4. I join a photography club, and all members love _______________.
A.take
B. taking
C. make
D. making
5. We ________ swimming because it’s fun and good exercise.
A. like
B. are liking
C. will like
D. liked
PT
13 tháng 4 2017
Porto is the second largest city in Portugal after Lisbon . It (1)...is... one of the major urban areas of the Iberian Peninsula.Located along the Douro river estuary in Northem Portugal. Porto is oen of the oldest European centres. (2) ...In..... 1996 ,UNESCO reognised its historic centre as a Word Heritage Site .Among the architectural highlights of the city . Porto Cathedral is (3)...the.... oldest surviving structure .It attracts millions (4).......of.... tourists every year
Gọi số tuổi của 3 người lần lượt là a,b,c
Ta có: a=2b=c+10
=> b=1/2 a; c=a-10
Do đó : a+b+c=30
hay a+1/2a+a-10=30
=> a+1/2a+a=40
5/2a=40
Nên a= 16
Từ đó ta suy ra b=8 ;c=6
Vậy số tuổi của ba bạn lần lượt là 16;8 và 6
Chúc bạn làm bài tốt :)
Call three chirle is a,b,c
I have: a= 2b = c+10
=> b =\(\frac{1}{2}\) a+a=10+30
=>a+\(\frac{1}{2}a+a-10=30\)
\(=>\frac{5}{2}a=40\)
*that you have to:a=16
And three chirlen are: b= 8 c=6
a=16
That well~ :>