Math Master Help Little Brother There are 2 sixth grade questions that won t

After using some of the oil, 4/5 of a barrel of oil is exactly 80 kilograms, if the remaining 5/8 is used, how many kilograms are shared between the two times?

In common. 80 4 5 100 kg.

The first time I used it.

100 80 20 kg.

Used it for the second time.

80 5 8 50 kg.

Shared twice. 20 50 70 kg.

The total length of the two ropes is 100 meters, and the first rope is 1/3 shorter than the second, how many meters are the two ropes long?

The first rope is the second rope.

The second rope is long.

100 (1, 2, 3) 60 meters.

The first rope is long.

60 2 3 40 meters.

The total amount of oil is 80 divided by (4/5) and the first time 20kg is used, and the remaining 5/8 is 50kg

So together 20 + 50 = 70kg

The first one is 3/3 shorter than the second = the first one is 2/3 of the second, so 5/3 of the second = 100m

The first is 40m and the second is 60m

The original oil 80 (5 4) = 100 kg, and a total of 100 * (1 5) + 80 * (5 8) = 70 kg was used twice;

100 [1 + (2 3)] = 60 meters, 60 * (2 3) = 40 meters, so the two ropes are 60 meters and 40 meters long.

Question 1: Total oil = 80 5 4 = 100 kg, use 100-80 = 20 kg;

Use the remaining 5 8 = 80 5 8 = 50 kg;

Shared oil loss: 20 + 50 = 70 kg.

Question 2: Let the length of the second rope be x

x+x (1-1 3) = 100, x = 60 m; (i.e. the second rope is 60 meters long) The length of the first rope is: x (1-1 3) = 40 meters.

(24+36) (36-24) 2=360 360 400 No.

6 4 10 = 240 (cm) But the net content cannot = box volume.

cm ) 6 cm ) scheme: 6 cans in a row, 4 rows. Materials: (4 6) (6 6) 2 = 1728 (cm) 6 4 12 2 = 576 (cm).

6 6 12 2 + 1728 + 576 = 3168 (cm) = decimeter ) 8 8 (2 + 5) = 448 (cm).

(1) Because it is a continuous number, the median (30) is the average of these thirteen numbers: 30 * 13 = 390 400 2) 6 * 4 * 10 = 240 is not the net content (and the carton).

3）s=2*pai*3*3+6*pai*12=90pai

Question 1: There are a total of 13 rows 24 and 36 are counted, so add 1 36-24 + 1 = 13 rows.

This problem is the same as finding its area, the knowledge learned in the fifth grade.

It is also the total number of seats = (number of seats in the first row + number of seats in the last row) and number of rows 2

So (24+36) 13 2=390 is enough.

Question 2: First of all, you must know that volume includes skin, and volume is only the volume inside, generally speaking, the volume of an object is always its volume.

If the thickness is not counted, then, its volume = its volume.

Box volume = 6 4 10 = 240 cubic centimeters ( chemical units) 240 cubic centimeters = 240 milliliters.

The volume (including the skin) is only 240 ml, and the volume is said to be 250 ml, at this time the volume volume is absolutely impossible, so there is a falsehood.

Question 3: The first question is to find its surface area because there is a cover.

Side area + bottom area 2

6 12 + (6 2) square 2 = square centimeter.

Second question: There should be 6 in a row, there are 4 rows.

At this time, the packaging should be cuboidal, that is, the length is 6 6 (one is 6 in diameter, and the other is 6 in a row), the width is 4 6, and the height is 12

So the surface area of the box = (36 24 + 36 12 + 24 12) 2 The answer is to calculate it yourself.

Question 4: This question is to find the volume of the column of water raised by the iron block, the bottom of the column of water is the same as the bottom of the container, 8 8 = 64 square centimeters.

The volume of the iron block = the volume of the water column 2 cm high + the volume of the overflowing water.

The volume of the overflowing water = the volume of the 5 cm water column.

So the volume of this iron block = the volume of 7 cm water column.

64 7 = 448 cubic centimeters.

1. This question is actually about calculating the area of a trapezoid. From the question, we can get that the two bottom edges are trapezoidal with a height of 13, and the area is (24+36)*13 2=390, <400

2. This question is to calculate the volume of a cube, and the outer packaging volume is 6 * 4 * 10 = 240, and the standard net content is 240, of course, it cannot be reached, because there is also the thickness of the packaging.

3. Do it yourself, looking for answers on the Internet will only make you not improve.

4. Ibid.

1. It can accommodate 390 pieces, and the difference is 10 pieces;

2. It does not exist; 3,

1 can seat 400 people. 2 is false, 6 * 4 * 10 is equal to 240 (including packaging), the static content is definitely less than 240.

（1）（24+36）/2 *13=390

2) s=6*4*10=240 Because there is only thickness, there is falsehood.

1) 36-24=13 (row) (24+5) * 13 = 377 (person) 377<400 Answer: You can't sit down.

2) 6 * 4 * 10 = 240 (cubic centimeters), because this number includes the volume of the box, so the net content should be less than 240 cubic centimeters, so the description is false.

3) 6 * 12 + 9 * 2 = 90 (square centimeters).

1. Yes, there are only 360 seats in total, which requires knowledge of the number sequence.

2。No, its volume is 240 cubic centimeters, which is 240 milliliters, which means that it can hold 240 milliliters of liquid.

3.The production of one needs to be squared centimeters; Packing: Packed in a 4x3x2 manner. 2304 square centimeters of cardboard are required.

cubic centimeters, subtract the volume of the remaining water from the volume of the entire container.

Set A to be x years old and B y years old.

y-(x-y)=4

x+(x-y)=61

x=42 y=23

The youngest one is 23 years old.

The younger ones are x years old, and the older ones are y years old.

y-(x-4)=x

x+(61-y)=y

x=23y=42

The youngest one is 23 years old.

1.120 (1+20%)=100 yuan on the first day, 120 (1-20%)=150 yuan on the second day.

2.290 (1-10%+70%)=$3 （1+10%）*1-10%）=99%4.

10*9-9*9）/（10*9）=10%5.5 [80%-(1-3 5)] = kilograms.

1,、The first batch of purchase price 120 The second batch of purchase price (

The maximum area is 2*5=

Still need to use equations? That's enough.

So many questions, no points, floated by.

The central angle of the fan chart is 360°, and the rose tree accounts for 52%, so use 360° 52%=. Chrysanthemum trees account for 18%, use 360° 18%=. If the tree is planted with 30%, use 360° 30%=180°

The central angle of the fan of a tree representing roses is (360x52%=) degrees, the central angle of a tree representing chrysanthemums is (360x18% = ) degrees, and the central angle of a tree representing lilies is (360x30%=108) degrees.

The fan-shaped central angle of the rose tree is 360*52%=degrees).

The fan-shaped center angle of the chrysanthemum tree is 360*18%=degrees).

The fan-shaped central angle of the lily tree is 360*30%=108 (degrees).