The cost price of a piece of clothing is 100 yuan, and it is priced at 40% profit rate. In order to attract customers, the merchants sell clothes 10% off 1: What's the actual price of this dress? 2: what's the final profit rate of this dress?

1：100×（1+40%）×90%,
=100×1.4×0.9,
=126 yuan;
2：（126-100）/100*100%
=26%；
A: the actual price of this dress is 126 yuan, and the final profit rate of this dress is 26%

The cost price of a garment is 100 yuan, and it is priced at 40% profit rate. In order to attract customers, the merchant sells the product at 10% discount
How much is the actual price of this dress
What's the final profit rate of this dress?
A bookstore bought 40 books at 960 yuan and found that 10 of them were damaged
1) The shopkeeper sells the intact books for 67.2 yuan each. What's the profit rate of these books (including 10 damaged ones)?
2) The shopkeeper sells the damaged books at a loss rate of 20%. How much is the price of each book?

1. Price 100x (1 + 40%) = 140
Sales price 140x90% = 126
2、126-100=26
26÷100=26%
2、 1, (40-10) x67.2 = 2016
2016-960=1056
1056÷960=110%
2、960÷40=24
24X（1-20%）=19.2

The price of a commodity is increased by 20% according to the cost price, and then it is sold at a 10% discount. The price is 270 yuan. What is the cost price of this commodity______ Yuan

Suppose the cost price of this commodity is x yuan, from the meaning of the question: 0.9x (1 + 20%) = 270, the solution: x = 250

How to make amber with pine resin

Amber production materials: high quality rosin, alcohol lamp, beaker, animal and plant specimens, small cartons, wax paper
Production method:
(1) Melting: melt high quality rosin in glass container
(2) Casting: first pour 1 / 3 rosin into the small carton to make the lower layer (lined with a layer of wax paper). Then put the animal and plant specimens into the carton, and then pour in the upper layer of rosin. After the rosin hardens, tear off the carton, and use a sharp knife to cut off the excess parts around the specimen to make the amber blank
(3) Polishing: at this time, the five sides of amber are rough, and you can't see the inside clearly. You have to wash it with alcohol and dry it in the air
be careful:
(1) To melt rosin, add asbestos mesh under the beaker. Otherwise, high temperature will deepen the color and affect the transparency
(2) Melt the rosin, stir gently with a glass stick, let the bubbles run out, and then pour into the carton
(3) When washing the blank, dip your fingers in alcohol, rub it back and forth in the opaque part of the specimen until it looks transparent, and then dry it. The washing time should not be too long, and it should be completed in three or four minutes; otherwise, the rosin of the specimen will melt and soften
Because the quality of rosin is brittle and fragile, it is a flaw in the ointment

Is amber a turpentine ball on a pine tree?

It was 20 million to 137 million years ago, but it was petrified later

Is amber a turpentine

Yes

Calculate how many moles of oxygen are consumed and how many moles of MgO are produced when 2 moles of MgO are burned in air

More than 0 and less than 1 mole
The amount of MgO formed is between 0 and 2 moles
3Mg+N2=Mg3N2
There will be magnesium nitride

How many moles of oxygen are consumed by burning 2 moles of magnesium belt in the air and how many moles of magnesium oxide are generated simultaneously? Emergency

2mg + O 2 = 2mg O 2 molar magnesium strip burns in air to eliminate 1 mole of oxygen and generate 2 moles of magnesium oxide at the same time

At present, 1 mole of magnesium completely reacts with oxygen. How many moles of oxygen are needed? How many moles of magnesium oxide are produced?

According to the equation directly, the dilution ratio is equal to the mass ratio of the substance
2Mg+O2=2MgO
2 1 2
1 x y
x=0.5 y=1
So 0.5mol oxygen is needed to produce 1mol magnesium oxide

The combustion of magnesium strip in air produces magnesium oxide and magnesium nitride, and the products are dissolved in water
The excess hydrochloric acid is neutralized with 20ml 0.5mol/l caustic soda solution, and then excess alkali is added to the solution to evaporate all ammonia and absorb with dilute hydrochloric acid. The weight of dilute hydrochloric acid is increased by 0.17g
A.0.24g B.0.48g C.0.72g D.0.96g
Please explain the following method,

1. [then add excess alkali to the solution, steam out all ammonia and absorb it with dilute hydrochloric acid. The weight of dilute hydrochloric acid is increased by 0.17g]
It shows that the NH3 absorbed by hydrochloric acid is 0.17g, and 0.17g divided by 17g / mol is equal to 0.01mol ammonia
2. [50 ml of 2.0 mol / L hydrochloric acid, then 20 ml of 0.5 mol / L caustic soda solution to neutralize the excess hydrochloric acid]
Note that after adding magnesium oxide and magnesium nitride to hydrochloric acid, 0.01 mol of free hydrogen ion is left
3. 0.08 mol of H + reacts with MgO and MGN when 0.01 mol of H + is neutralized with NH3
The formula is MgO + 2H + = Mg2 + + H2O or Mg3N2 + 6h + = 3mg2 + + 2nh3
The ratio of H + to Mg is 2:1, Mg is 0.04mol, 0.04mol × 24g / mol = 0.48g

The cost price of a piece of clothing is 100 yuan, and it is priced at 40% profit rate. In order to attract customers, the merchants sell clothes 10% off 1: What's the actual price of this dress? 2: what's the final profit rate of this dress?