The weight ratio of a and B is 4:1. If 10 g is taken from a and put into B, the weight ratio of a and B is 7:5, how many G is there There are two piles of coal, the first pile carries 1 / 3, the second pile carries 3 / 5, the weight of the remaining first pile and the second pile is 3:5, the first pile of original coal is 360 tons, and the second pile of original coal is how many tons?

The weight ratio of a and B is 4:1. If 10 g is taken from a and put into B, the weight ratio of a and B is 7:5, how many G is there There are two piles of coal, the first pile carries 1 / 3, the second pile carries 3 / 5, the weight of the remaining first pile and the second pile is 3:5, the first pile of original coal is 360 tons, and the second pile of original coal is how many tons?

Arithmetical method: if the total number remains unchanged as "1", the original a accounts for 4 / (4 + 1) = 4 / 5 of the total number, and then a accounts for 7 / (7 + 5) = 7 / 12 of the total number, so the total weight is 10 / (4 / 5-7 / 12) = 600 / 13, then the original A is 600 / 13 * 4 / 5 = 480 / 13 (g)

It costs 68000 yuan for a clothing store to buy 80 sets of first-class suits and 50 sets of second-class suits from the wholesale market. At retail, the price of each first-class suit is increased by 30% and that of each second-class suit is increased by 20%. After all the suits are sold, the total price is 86400 yuan. What is the wholesale price of each first-class suit?

Suppose the wholesale price of A-class suit is x yuan, then the wholesale price of B-class suit is (6.8-80x) / 50. According to the above conditions, the following equation can be formulated: 80 (x + 30% x) + 50 ((6.8-80x) / 50 + 20% [(6.8-80x) / 50] = 8.6480 * 1.3x + 50 * 1.2 [(6.8-80x) / 50] = 8.64, both sides multiply by 50, as follows: 50 * 80 * 1.3x

There are four different natural numbers a, B, C, D, except 0. If you sum them, you can get six different numbers. These six different numbers are arranged from small to large, which is exactly an arithmetic sequence. There are many groups of a, B, C, d that meet the conditions. Try to find the minimum value of (a + B + C + D) by enumeration
Hurry!

Let a be less than B, less than C, less than D, and y be their sum, that is, to find the minimum value of Y. we know that the sum of two pairs is an arithmetic sequence, we can know that the tolerance is d-c or C-B, we can know that C = (D-B) / 2, then y = a + 3 / 2D + B / 2, we consider using linear programming method or function extremum method to solve this problem. The rest is for me to complete!