A cuboid becomes a cube when its height increases by 4cm. At this time, its surface area increases by 112cm. What is the surface area of the cuboid?

A cuboid becomes a cube when its height increases by 4cm. At this time, its surface area increases by 112cm. What is the surface area of the cuboid?

Obviously, the bottom of the cuboid is square
Let the edge length be a and B respectively
A = B + 4 can be listed by the title
2（a²+2ab）+112=6a²
The solution is a = 7, B = 3
So the surface area of the cuboid is 6A & sup2; - 112 = 182

In a cube with 4 cm edge length, dig out a small cube with 1 cm edge length. The volume of the remaining three-dimensional figure is () cubic centimeter, the maximum surface area is () square centimeter, and the minimum surface area is () square centimeter

The volume is 4x4x4-1x1x1 = 63
The maximum surface area is 4x4x6 + 1x1x4 = 100
The minimum surface area is 4x4x6 = 96

There are four cubes with red paint on the surface, and their edge lengths are 1, 3, 5 and 7. These cubes are sawed into small cubes with edge lengths of 1. At least one of the small cubes is red______ One

1 + [33 - (3-2) 3] + [53 - (5-2) 3] + [73 - (7-2) 3], = 1 + 26 + 98 + 218, = 343 (pieces); answer: at least one face is red, a total of 343; so the answer is: 343

1. The number of male students in class 5 (1) is twice that of female students. The average weight of male students is 42 kg and that of female students is 36 kg?
2. Six (2) 42 students take a group photo as a souvenir. If you take a 7-inch group photo, you can send 2 photos. The cost is 10.4 yuan. If you need to print more photos, you will charge 1.42 yuan for each one. If everyone has a photo, how much does it cost per person on average?

36 + (42-36) × 2 △ 3 = 40 kg
(10.4 + 1.42 × 40) △ 42 = 1.6 yuan

Primary school fifth grade Olympiad mathematical starting line answer? To have a formula ah? You heroes help me!

The circumference of the first lane of standard semicircle track and field field field is 400m. Its radius has different design schemes, such as 36m, 36.5m, 37.898m, etc
（1） Calculation of runway perimeter (first lane perimeter)
1. According to the circle formula C = 2 π R, then the length of the two curves of the first lane (calculated line length) is:
2 × 3.1416 × (36 + 0.30) M = 228.08m, the length of a bend is 228.08 △ 2 = 114.04m
2. Calculation of straight section length
Length of two straight sections = total length of Runway - length of two curves
=400m – 228.08m=171.92m
The length of a straight section is 171.92m △ 2 = 85.96m
3. Total length of runway = two curves + two straight sections
=228.08m+171.92m
=400m
（3） Calculation of the length of each branch curve (taking the branch width of 1.22m as an example)
According to the circle formula C = 2 π R
Cn=2π[r+（n-1）d+0.20]
(C is the circumference of the curve, n is the number of times, R is the radius of the site, D is the width of the lane)
（3） The calculation of the forward extension of the starting line
If the athletes on the two lanes run one week according to their own lane, the athletes on the second lane will run 7.04M more than the athletes on the first lane. In order to make the distance of the second lane equal to the distance of the athletes on the first lane, the starting point must extend a distance forward, It is called the starting line extension. The method to calculate the starting line extension is to subtract the length of the first lane from the length of the curve of a certain lane, that is, the starting line extension of the lane. The formula is as follows:
Wn=2π[r+（n-1）+0.20]-2π（r+0.30）
Length of each track of conventional runway:
Runway length (m)
1 400
2 407.04
3 414.70
4 422.34
5 430.03
6 437.70
7 445.36
8 453.03
In order to be fair, the distance of extra running is subtracted at the start, so the starting position of the athletes is different, the closer to the outside, the more forward

There is a cube block with different natural numbers written on each surface, one of 1, 2, 4, 8, 16, 32. If one or more of the cubes can be seen at the same time, the sum of the numbers on these surfaces can be obtained at most________ There are two different numbers

There are six cases of only one face;
It can be seen that the case of two faces is a combination of 2 out of 6, that is, 15;
The case that three faces can be seen is a combination of 3 out of 6, that is, 20;
The total is 6 + 15 + 20 = 41

If the time indicated by the hour hand is exactly 18 o'clock, then the minute hand will turn 1990 times______ It's five o'clock

1990 △ 24 = 82 (days) The original clock indicates that the time is 18 o'clock, plus the remaining 22 hours, 40 hours, 40 / 24 = 1 (day) 16 hours. This 16 hours is the time after the minute hand rotates for 1990 turns

Divide 430 apples and 248 pears into several baskets averagely. The number of water fruit baskets is between 30-50. At the end of the distribution, there are 10 apples left and 4 pears left. How many water fruit baskets are there? Please list the calculation process

The number of apples to be divided is 430-10 = 420, the number of pears to be divided is 248 + 4 = 252, 420 = 2 × 2 × 3 × 5 × 7252 = 2 × 2 × 3 × 3 × 7, the common divisor between 30-50 is 2 × 3 × 7 = 42, so the number of water fruit basket is 42

October 1, 1995 is Sunday, March 8, 1995 is working women's day?

March 8-october 1, 1995
Total: 24 + 30 + 31 + 30 + 31 + 31 + 30 + 1 = 308 days (including October 1)
308 / 7 = 44 cycles
So March 8 is Saturday

1. What is the remainder of 16589432916584329 divided by 25?

1、2005×0.375—0.375×1949＋3.75×2.4=200.5*3.75-3.75*194.9+3.75*2.4=3.75*(200.5-194.9+2.4)=3.75*8=302、（123456789.1×123456789.1）—123456789×123456789.2=（123456789.1×123456789.1）—(123456789.1...