Second, 1.50 seconds 2.6.75 square centimeters

3.3x+ 13 = 2(x+ 13)4.2 10

5.300,200 6.700 7.29 8.6

3. 1. The length of each floor tile is 45cm and the width is 15cm. (Hint: If the length of each small rectangle is x, the width is 60-x, and according to the meaning of the question, x = 3(60-x). )

2. The distance between A and B is 108 km. (hint: let the distance between a and b be x km. According to the meaning, x-36=36 +36, x = 108. ) 5438+00-8 12.

3. Teacher Xue took eight students. (Hint: Suppose Mr. Xue brings X students, which is 50(x+ 1)×80% = 50x×90%. )

4. 1.( 1) The stock of raw grain in granaries A and B is 270 tons and 180 tons respectively. (Hint: Assume that the raw grain storage capacity of granaries A and B is X tons and (450-x) tons respectively. According to the question, it means 1-? 3x =5？

1 -? 2(450 -x)。 )5?

(2) The grain of granary A supporting granary C is 3×270 = 162 (ton), and that of granary B supporting granary C is 2× 180 =72 (ton). The sum of granaries A and B is * * * 55% of granary C.

The grain is 162 +72 = 234 (ton), because 234 >: 200, so this allocation can meet the needs of C granary.

The retail price is set at 2.50 yuan per kilogram. (Hint: Open a store to buy m kilograms of apples, and the retail price is X yuan per kilogram. According to the question, it means (1.2m+400×1.50× m )×1000.

( 1+25%)=( 1- 10%)MX。 ) the ability to surpass oneself.

1. The total distance that dogs run is 37.5 kilometers. (hint: suppose it takes x hours for A to catch up with B. According to the meaning of the question, it is 5x = 3x+5, and the solution is x = 2.5. The total distance that dogs run is 15 ×2.5 =

37.5.)

2. The company should choose the construction team, and the cost payable to the construction team is 30,000 yuan. (Hint: If the work efficiency of Team B is X, the work efficiency of Team A is 2x. According to the meaning of the question, x is obtained.

+2x = 1，x = 1，2x = 1。 Therefore, it takes 30 days and 60 days for Party A and Party B to complete this project alone. If these two construction teams are allowed to work alone, they will have to deal with Team A 206030.

30 × 1000 = 30000 (yuan), which should be paid to team B, 60 ×550 = 33000 (yuan), so the company should choose the construction team, and the fee payable to the construction team is 30000 yuan).

book