Số các số có 3 chữ số chia hết cho 3 là : (999-102 ): 3 + 1 = 300( số)

Số đoạn dây có thể cắt được là:

 8,5 : 2,5 = 3,4 ( đoạn)

Đáp số : 3 đoạn

2 số tự nhiên được viết dưới dạng n và n+1 

Ta có: n.(n+1)= 3306

=>    57.( 57+1) = 3306

Vậy n = 57  và n+1 =58 

Hai số tự nhiên liên tiếp đó là: 57 ; 58

Tỉ số là 3/5

Kết quả phép tính trên là:

      123 + 145 + 234 + 23 - 35 - 67 = 423

            Đáp số: 423

Rewritting

1. Dublin is the capital of Ireland. It is my favourite city.

=> Dublin which is the capital of Ireland is my favorite city.

2.Amelia speaks English and Chinese fluuently. Her mother is from Shanghai

=> Amelia whose mother is from Shanghai, speaks English and Chinese fluently.

3.This is smartphone takes great photos. I bought last week

=> The smartphone which I bought last week, takes great photos.

4.Buckingham Palace is in the centre of London. The Queen of England lives in

=> Buckingham where the Queen of England lives in is the centre of London.

5. Ferraris are very expensive. They are made in Italy

=> Ferraris which are made in Italy are very expensive.

6.Russell Crowe was born in New ealand. He starred in Gladiator

=> Russell Crowe who was born in New Zealand starred in Gladiator.

7.Emily is in my English class. Her brother is a singer

=> Emily whose brother is a singer is in my English class.

8.Mr Kemp is going to retire next year. He teaches us Physics

=> Mr. Kemp who teaches us Physics is going to retire next year.

9.The White House is in Washington DC. The US president lives in

=> The White House where the US president lives in is in Washington DC.

10.My brother earns a lot of money. He works in Warsaw

=> My brother who works in Warsaw earns a lot of money.

số bé là:

(54+6):(5-1)=15

số lớn là:

54+15=69

tuổi bố hiện nay :

4 : ( 2/5 x 1/3 ) = 30 ( tuổi )

đáp số : 30 tuổi