Xiao Ming and Xiao Gang are about 1.7 * 10 & sup2; in height, but is Xiao Ming right when he says, "Xiao Gang is 9cm shorter than me"

Xiao Ming and Xiao Gang are about 1.7 * 10 & sup2; in height, but is Xiao Ming right when he says, "Xiao Gang is 9cm shorter than me"

be on the cards
A is 9 cm higher than B
And the height of a and B is 170 cm after rounding
Then a 1 74 cm B 165 cm

Xiao Ming and Xiao Gang are about 1.8 * 10 ^ 2cm tall, but Xiao Ming said: Xiao Gang is 9cm shorter than me. Is that possible? Give the reason

Yes, 1.8 * 10 ^ 2cm, two significant digits are reserved, and the maximum value is 184.499999
It is possible to take 175.00000000... 001 as the minimum, with a difference of 9cm

Xiaoming is 10 cm higher than Xiaogang, and Xiaogang is 15 times shorter than Xiaoming

Xiaogang 140cm, Xiaoming 150cm

Which three gorges does the Three Gorges refer to

Three Gorges
From ancient to modern times, the Three Gorges, a magnificent grand canyon in the Yangtze River, is one of the ten great scenic spots in China. It rises from the white city of Fengjie County in Sichuan province to the south of Hubei, Yichang, and is composed of Qutang gorge, Wuxia gorge and Xiling gorge. The total length is 192 km, of which 90 km is the canyon.

The problem of equivalent infinitesimal of higher numbers
The N times of √ (1 + √ (x + √ x)) - 1 (x → 0) and m * x are equivalent infinitesimals. What is m = and what is n equal to,

√(1+√(x+√x))－1
=[√(1+√(x+√x))+1]/√(x+√x)
Equivalent to 2 / √ x = 2x ^ (- 1 / 2)
So: M = 2, n = - 1 / 2

There are 50 students in class 61. Boys account for three fifths of the class. One third of the boys are good students. How many good students are there in class 61?

50 * 3 / 5 * 1 / 3 = 10
First confirm the number of male students: 50 * 3 / 5 = 30
Reconfirmation of three good students among boys: 30 * 1 / 3 = 10

28+31+30+32+29+28+31
Simple calculation

28+31+30+32+29+28+31
=(28+32)+(31+29)+30+28+31
=60+60+60+29
=180+29
=209

If the number of items is 2n + 1, the arithmetic sequence is obtained. The sum of all odd items is 165. The sum of all even items is 150, n =?

Odd n + 1 term
So [A1 + a (2n + 1)] * (n + 1) / 2 = 165
Even n terms
And the first and last terms and A2 + A2N = a1 + a (2n + 1)
So [A1 + a (2n + 1)] n / 2 = 150
Division (n + 1) / N = 165 / 150 = 11 / 10
n=10

There are 7 pieces of RMB of 5 yuan and 10 yuan, totally 60 yuan. How many pieces of RMB of 5 yuan? How many pieces of RMB of 10 yuan

Assuming that all are 5 yuan, there should be: 5 × 7 = 35 yuan
Less than actual: 60-35 = 25 yuan
You can add 10-5 = 5 (yuan) by replacing a 5 yuan one with a 10 yuan one
The number of 10 yuan sheets is: 25 △ 5 = 5 (sheets)
5 yuan: 7-5 = 2 (sheets)

(1) find the rule and fill in the number: 0,1,1,2,3,5 () ()
There are also some (2) if a multiplied by B is equal to a of B + B of a, find the value of (3 * 2) - (2 * 3). (3) there is a batch of parts, which can be completed by the master alone for 15 hours, and the apprentice alone for 25 hours. We also know that the master and apprentice work together for a total of 400 parts in 5 hours, and find the total number of these parts. (4) the distance between AB and a is 108 km, and a starts from a to B by bike, and the speed is 20 km per hour, B starts from B to a at a speed of 4 kilometers per hour. If B starts at 8 a.m. at the same time, when is the distance between the two players 36 kilometers? (5) there are 16 football teams in a single round robin game. They are required to win one game and get 3 points, draw one game and lose one game and get 0 points. A team gets 28 points compared with the end of the game. Please guess the situation of the team's game