The weight ratio of package a and package B is 4:1. If 13 grams are taken from package a and put into package B, the weight ratio of package a and package B becomes 7:5, then what are the weights of the two packages?

The weight ratio of package a and package B is 4:1. If 13 grams are taken from package a and put into package B, the weight ratio of package a and package B becomes 7:5, then what are the weights of the two packages?

Total weight: 13 △ 44 + 1-77 + 5, = 13 △ 45-712, = 13 △ 1360, = 60 (kg); a: 60 × 45 = 48 (g), B: 60 × 15 = 12 (g). Answer: the original caramel is 48 g, caramel is 12 G

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A real estate company in a real estate, received a commission, the amount of 6% of the sales price, if the sales price minus the gold price of the real estate is 84000, then how much is the sales price?
If the selling price is 250% of the original purchase price (the purchase price is 36000), what is the selling price?
These two questions involve a question of sales price, purchase price and commission. By the way, what's the relationship between these items?

Sales price = 84000 / (1-6%) = 87500 yuan
The selling price is 87500 yuan
36000 * 250% = 90000 yuan
The selling price is 90000 yuan
If your company doesn't have one, I'll make my own decision

A and B vehicles drive from city a and city B to City C along the expressway at the same time. It is known that the distance between city a and City C is 450 km, and that between city B and City C is 400 km
If the speed of car a is 5 / 4 of that of car B, the result is that car a arrives at City C 1 / 2 hours earlier than car B, and the speed of car B is calculated. 2. If car a is a km / h faster than car B, when car B's speed is 9A km / h, which car gets to City C first? Please give reasons:)

1.400 × 5 / 4 = 500 500-450 = 50 50 / 2 = 100 (km / h)
100 × 4 / 5 = 80 (km / h)
2.9a+a=10a 10a:9a=10:9 450:400=9:8
10: 9 ＜ 9:8 B bus comes first

2x-1-2x + 5 = 6x-7-1

The solution of the equation is x = 0

The distance between Party A and Party B is 540km. The passenger cars and freight cars leave from Party A and Party B at the same time. After meeting for three hours, it is known that the passenger cars travel 95 kilometers per hour
95km. How many kilometers does the truck travel per hour?

540÷3-95
=180-95
=85 (km / h)
A: the truck travels 85 kilometers per hour

What is the number on the 99th place after the decimal point? 199? How to calculate?

5 / 7 is a circular decimal. Just master the law of circulation
5/7=0.714285 714285 714285 714285 714285 71
Six numbers in a cycle, divide 99 by 6 and leave 3, so it's the third bit, 4
199 the same

A. B is 360 km away from the two places. Car a and car B leave from the two places at the same time and meet after four o'clock. How many kilometers does car a travel every hour and car B travel every hour? (calculated by two methods)
There must be equations to calculate

The first type (360-4 × 50) △ 4 = 40
The second type: set B car to travel x kilometers per hour
4×50+4X=360
X=40

In the triangle ABC, if B equals 60 degrees and 2b equals a plus C, we prove that the triangle ABC is an equilateral triangle

Cosine theorem B ^ 2 = a ^ 2 + C ^ 2-2accosb
B ^ 2 = a ^ 2 + C ^ 2-ac, (a + C) ^ 2 / 4 = a ^ 2 + C ^ 2-ac, a = C, isosceles triangle, B equals 60 degrees, triangle ABC is equilateral triangle

The two passenger and freight cars leave from a and B at the same time and meet in 4.5 hours. When they meet, the passenger car travels 27 kilometers more than the freight car. The speed of the freight car is 4 / 5 of the speed of the passenger car. How many kilometers are there between a and B?

The passenger car runs x km per hour and the freight car runs 4 / 5x km
4.5x-4.5×4/5x=27
x=30
4.5X + 4.5 × 4 / 5x = 135 + 108 = 243km

Given that the average of a group of data 1, 2, 0, - 1, x, 1 is 1, then the range of this group of data is 1______ ．

1 + 2 + 0-1 + X + 1 = 1 × 6, so x = 3, then the range of this group of data = 3 - (- 1) = 4