A cuboid with a height of 40 cm and a square bottom will increase its surface area by 80 square cm if its height is increased by 5 cm. Find the surface area and volume of the original cuboid

A cuboid with a height of 40 cm and a square bottom will increase its surface area by 80 square cm if its height is increased by 5 cm. Find the surface area and volume of the original cuboid

Perimeter of bottom surface = 80 △ 5 = 16 (CM)
Side length of bottom surface = 16 △ 4 = 4 (CM)
Original surface area = 4 × 4 × 2 + 4 × 40 × 4 = 672 (square centimeter)
Original volume = 4 × 4 × 40 = 640 (cm3)

If the height of a cube is increased by 4cm, it will become a cuboid. The surface area of the cuboid is just 80 square percent more than that of the original cube
Meters to find the volume of the original cube

The taste of home happiness
Let the length of the original square be n cm
5N & # 178; = 80 (added five faces)
n²＝16
n＝4（cm）
Cube volume = (4cm) & # 179; = 64cm & # 179;
A: the volume of the original cube is 64 square centimeters
Good luck and goodbye

About the scale unit
A car goes from Huai'an to Nanjing at a speed of 90 kilometers per hour (that is, 1 cm = 90 kilometers). The distance between Huai'an and Nanjing is 2 cm. It starts at 8 am. When can it arrive?

Analysis: 1 cm = 90 km, 2 cm is equal to 90 × 2 = 180 km, 180 km is the total distance from Huai'an to Nanjing, 180 △ 90 = 2 (hours) this is the time from Huai'an to Nanjing, 8:00 + 2 hours = 10:00, so it is 10:00 in the morning
90 × 2 = 180 (km) 180 △ 90 = 2 (H) 8 hours + 2 hours = 10 hours
A: it will arrive at about 10 a.m

"24" point game, take any four natural numbers between 1 and 13 for rational number mixed operation, so that the result is equal to 24, there are four rational numbers 2,4,7,10, please run
Each number is limited to one time

2*4*(10-7)=24
10+7*(4-2)=24

1. Decomposition factor: (1-x power) (1-y power) + 4xy
2. Factorization factor: the quadratic power of X - the quadratic power of x-2y-4y
3. Factorization factor: the quadratic power of 4x - 4xy + the quadratic power of Y - 44x + 22y + 40
4. Factorization factor: the third power of X, the second power of Y - the second power of 5x, the second power of Y - the second power of 24xy

(1-x^2)(1-y^2)+4xy =1-x^2-y^2+x^2y^2+4xy=(x^2y^2+2xy+1)-(x^2-2xy+y^2)=(xy+1)^2-(x-y)^2=(xy+x-y+1)(xy-x+y+1)x^2-x-2y-4y^2 =(x^2-4y^2)-x-2y=(x+2y)(x-2y)-(x+2y)=(x+2y)(x-2y-1)4x^2-4xy+y^2-44x+22y+40 =(2x...

A batch of goods with 17 trains from a city to B city at the speed of V km / h. The distance between freight cars should not be less than (V / 20) ∧ 2 km
A batch of goods from a city to B city with 17 trains at a constant speed of vkm / h. given that the distance between freight cars should not be less than (V / 20) ∧ 2km, how many hours is the fastest time for all the goods to reach B city

T = 16 * [(V / 20) ^ 2 / v] + 400 / v = V / 25 + 400 / V > = 8 (hours)
In this case, V / 25 = 400 / v
v^2=10000
v=100km/h
A: it will take at least 8 hours and the speed is 100 km / h

How to calculate the area of triangle?

Multiply the bottom by the height and divide by two
Bottom × height △ 2
Typing is not easy, if satisfied, hope to adopt

The concrete used in construction site is made of cement, yellow sand and stone in the ratio of 2:3:5. (1) 120 tons of such concrete should be prepared
The concrete used in construction site is made of cement, sand and stone in the ratio of 2:3:5
(1) How many tons of cement is needed to make 120 tons of such concrete?
(2) If there are 36 tons of these three materials, when all the yellow sand is used up, how many tons of cement are left and how many tons of stones are added?

1. 120 * 2 / (2 + 3 + 5) = 24 tons, 2. There are 12 tons of cement left and 24 tons of stones added

The volume of a cylinder is 56.52 cubic decimeters, and the volume of a cone with the same base and height is () cubic decimeters
(2) The volume of a cone is 18.84 cubic decimeters, and the volume of a cylinder with the same base and height is () cubic meters
(3) Prepare a cone and a cylinder container with equal bottom and height. After the cylinder container can be filled with water, pour it into the cone container. When all the water in the cylinder container is empty, 36.2 ml of water will overflow. This is () ml of water in the cone container
(4) Three same cylinder billets can be fused into () cylinder parts with the same base and height as the cylinder

(2) The volume of a cone is 18.84 cubic decimeters, and the volume of a cylinder with the same bottom and height is (56.52) cubic meters

The minimum multiple of a number is 12, and the factor of this number is [a number is not only a factor of 16, but also a multiple of 16, and this number is []
For a four digit number, the number on the one digit is neither prime nor composite, the number on the ten digit is both prime and even, the number on the hundred digit is the smallest composite, and the number on the thousand digit is both odd and composite. The four digit number is []
The sum of the two primes is 18, and the product is 65. The two primes are 〔 and 〕
The final result is []

The minimum multiple of a number is 12. The factor of this number is [1, 2, 3, 4, 6, 12]. A number is not only a factor of 16, but also a multiple of 16. This number is a four digit number of [16]. The number on one digit is neither prime nor composite. The number on ten digit is both prime and even. The number on hundred digit is the minimum composite