Answer: 86 kg
Explanation:
To solve this problem, we can use a system of equations. Let's assign variables to represent the weight of one post and one bar. (Let "p" represent the weight of one post in kg. Let "b" represent the weight of one bar in kg.)
We are given two pieces of information:
1. Three posts and two bars weigh 25kg: 3p + 2b = 25
2. Two posts and three bars weigh 18kg: 2p + 3b = 18
Now, we can solve this system of equations. There are different methods to solve it, but let's use the substitution method.
From equation 1, we can express p in terms of b: p = (25 - 2b) / 3
Now, we can substitute this expression for p in equation 2: 2((25 - 2b) / 3) + 3b = 18
Let's simplify this equation: (50 - 4b) / 3 + 3b = 18
Multiply both sides of the equation by 3 to eliminate the fraction: 50 - 4b + 9b = 54
Combine like terms: 5b = 4
Divide both sides of the equation by 5: b = 4 / 5 = 0.8
Now, substitute this value of b back into equation 1 to find the value of p: 3p + 2(0.8) = 25
3p + 1.6 = 25
3p = 25 - 1.6
3p = 23.4
p = 23.4 / 3 = 7.8
So, we have found that the weight of one post is 7.8 kg and the weight of one bar is 0.8 kg.
To find the weight of 10 posts and 10 bars, we can simply multiply the weight of one post by 10 and the weight of one bar by 10:
Weight of 10 posts = 10 * 7.8 = 78 kg
Weight of 10 bars = 10 * 0.8 = 8 kg
Therefore, the weight of 10 posts and 10 bars is 78 kg + 8 kg = 86 kg.