The ratio of a and B is 5:3. 90 barrels are transported from a warehouse and put into B warehouse. The ratio of a and B is 2:3. How many barrels of original oil in B warehouse?

The ratio of a and B is 5:3. 90 barrels are transported from a warehouse and put into B warehouse. The ratio of a and B is 2:3. How many barrels of original oil in B warehouse?

90 (55 + 3-22 + 3), = 90 (58 − 25), = 90 (940), = 400 (barrel), 400 (3 + 5) × 3, = 400 (8 × 3, = 50 × 3, = 150 (barrel); answer: B barrel has 150 barrels of original oil

Two barrels of a and B weigh 240 kg in total. Pour two thirds of the water in barrel a into barrel B. at this time, the water in barrel a is one seventh of that in barrel B,
How many kilos did a and B have?
Put a square iron block with the edge length of 6dm into a cylinder container, and the water surface rises by 3cm after it is completely submerged. If a cone lead block is put into the middle period, the water surface rises by 1.5cm. What's the volume of this cone in square decimeter? (with proportional solution)
There are 4 boys less than 5% of the class and 4 girls less than 46% of the class. How many boys are less than girls in this class?

(1) Now B has: 240 (1 + 1 / 7) = 210 kg
Now a: 240-210 = 30 kg
It turns out that a has: 30 (1-2 / 3) = 90 kg
Original B: 240-90 = 150 kg
(2) Volume of iron block: 6 × 6 × 6 = 216 cubic decimeter
Let the volume of this cone be x cubic decimeter,
X：216=1.5：3
3X=216×1.5
3X= 324
X=324÷3
X=108
A: the volume of this cone is 108 cubic decimeters

The difference between a and B is 54. One seventh of a equals two fifths of B. what is B

Let a x B y
x-y=54
x/7=2y/5
The solution is x = 84, y = 30

If 2.5 kg is taken out of barrel a and put into barrel B, then the mass of barrel a and barrel B is equal. How many kg is there in barrel a and barrel B
(to calculate)

B weight = 2.5 * 2 = 5kg;
Weight of a = 5 * 2 = 10kg

There are two barrels of oil a and B. the mass of barrel a is twice that of barrel B. If 2.5kg oil is taken out of barrel a and put into barrel B
The quality of a and B is equal
How many kilos each of the two barrels of oil used to be?

2.5 × 2 ÷ (2-1) = 5kg
5 × 2 = 10kg

There are two barrels of oil. The quality of barrel B is 3 / 5 of that of barrel A. after 5 kg of oil is taken out of barrel a and put into barrel B, barrel B is 7 / 9 of that of barrel A. There are two barrels of oil?

5÷(5+3)=5/8
9÷(9+7)=9/16
Total: 5 ÷ (5 / 8-9 / 16) = 80 kg

The total weight of the two barrels of oil a and B is 60 kg. The weight of a is one third less than that of B. how many kg are the two barrels of oil?

Weight of a: 60 * (3-1) / (3 + 3-1) = 24kg
B weight: 60-24 = 36 kg

The two barrels of oil a and B are equally heavy. Pour 1 / 3 of barrel a into barrel B. the quality of barrel B oil is ()

(1 + 1 / 3) / (1-1 / 3) = 2 (Times)

Give 20 pears and 25 apples to the children. Each of them has the same number. As a result, there are two pears left and two apples left. How many children are there in this class at most?
There are two barrels of oil a and B. the oil quality of barrel a is twice that of barrel B. If 2.5kg oil is taken out of barrel a and put into barrel B, the oil quality of barrel a and B is equal. How many kilos each of the two barrels of oil used to be?

20-2=18
25+2=27
The greatest common divisor of the two is 9, that is, there are at most 9 children in this class

There are two barrels of oil. The weight of barrel a is 1.2 times that of barrel B. If you pour another 5kg of oil into barrel B, then the two barrels of oil will have the same weight. How many kg of oil are there in each barrel?
Note: do not use the equation!

The weight of a barrel of oil is 1.2 times that of B barrel of oil, so the mass of two equal barrels of oil is (1 + 1.2) / 2 = 1.1 times that of B barrel of oil
So 5kg is 1.2-1.1 times of the original B barrel oil = 0.1 times
So the mass of B barrel of oil was originally 50 kg
The mass of a barrel of oil is 60 kg