The total cost of two pieces of clothing is 500 yuan. In order to make a profit, the store owner decides to price the clothing at 50% of the profit and the clothing at 40% of the profit. In actual sales, at the request of customers, the two pieces of clothing are sold at a 10% discount. In this way, the store makes a total profit of 157 yuan. How much is the cost of the two pieces of clothing?

Suppose the cost of a clothing is x yuan, then the cost of B clothing is (500-x) yuan. According to the meaning of the question: 90% · (1 + 50%) x + 90% · (1 + 40%) (500-x) - 500 = 157, the solution is: x = 300500-x = 200

One kind of machine parts, cost reduced from 2.4 yuan to 0.8 yuan, cost reduced to a few percent? Please immediately

0.8÷2.4≈33.3%
A. cost reduced to 33.3%

The cost of a kind of machine parts has been reduced from 4.5 yuan to 2.5 yuan. How much has the cost been reduced?
Hurry

(4.5-2.5)/4.5*100%=44.44%
Cost reduced by 44.44%

3. (1) the original formula of 115 × 8 △ 15-85 △ 15 × 8 = 115 × 8 △ 15-85 × △ = (115-85)

115×8÷15-85÷15×8
Original formula = 115 × 8 × 1 / 15-85 × 1 / 15 × 8
=61/1/3-45/1/3
sixteen

27 × [(1000-109) △ 81] recursive equation calculation

=27*（891÷81）
=27*11
=297

The average of the five numbers is 43. If we arrange the five numbers from small to large, then the average of the first three numbers is 35, and the average of the last three numbers is 50. What is the number in the middle?

35 × 3 + 50 × 3-43 × 5, = 105 + 150-215, = 255-215, = 40

The average number of five numbers is 30. If the five numbers are arranged from small to large, the average number of the first three numbers is 25, the average number of the last three numbers is 35, and the number in the middle is 25______ ．

25 × 3 + 35 × 3-30 × 5, = 75 + 105-150, = 180-150, = 30; answer: the number in the middle is 30; so the answer is: 30

There are five numbers, four of which are selected at a time to calculate their average, and the other number is added to calculate five times in this way,
The following five numbers 24 27 29 32 38 are obtained respectively to find the smallest of the original five numbers
Elementary school formula steps,

Let five numbers be a B C D E respectively
E + (a + B + C + D) / 4 = 24: 4E + A + B + C + D = 96, equation 1
A + (B + C + D + e) / 4 = 27: 4A + B + C + D + e = 108, equation 2
B + (c + D + e + a) / 4 = 29: 4B + C + D + e + a = 116 equation 3
C + (D + e + A + b) / 4 = 32: 4C + D + e + A + B = 128 equation 4
D + (E + A + B + C) / 4 = 38, 4D + e + A + B + C = 152, equation 5
The sum of the five formulas is: 8 × (a + B + C + D + e) = 600
A + B + C + D + e = 75 equation 6
Subtract formula 6 from Formula 1 to get: 3E = 21, then E = 7
If 3A = 33, then a = 11, a > E
Similarly: d > C > b > a
So the minimum number is seven

There are five numbers in a row from small to large, the average of the first three numbers is 34, the average of the last three numbers is 45, the average of these five numbers is 40, and the median of this column is 40______ ．

(34 × 3 + 45 × 3) - 40 × 5, = 237-200, = 37; answer: the median of this column is 37

The average number of the five numbers is 40. If the five numbers are arranged from small to large, then the average number of the first three numbers is 34, and the average number of the last three numbers is 45. What is the median of this group of data?

34 × 3 + 45 × 3-40 × 5 = 102 + 135-200 = 237-200 = 37, so the median of this group of data is 37