An alloy contains zinc and copper in the ratio 7:9. Find the weight of copper if it has 31:5 kg of zinc
Zinc in 2 kg of new alloy = (5/13 + 5/8) = 105/104 kg
copper in 2 kg of new alloy = (8/13 + 3/8) = 103/104 kg
Ratio of zinc and copper in new alloy = 105/104 : 103/104 = 105:103
hope this example helps.....
To find the weight of copper in the alloy, you will need to use the given ratio between zinc and copper.
The given ratio is 7:9, which means that for every 7 parts of zinc, there are 9 parts of copper in the alloy.
Now, let's use this ratio to find the weight of copper when the weight of zinc is given as 31.5 kg.
First, you need to find the total number of parts in the given ratio. It can be calculated as the sum of the two parts: 7 + 9 = 16.
Next, you can calculate the weight of copper using proportions.
Since there are 7 parts of zinc in the ratio, and the weight of zinc is given as 31.5 kg, you can set up a proportion:
7 parts of zinc / 31.5 kg of zinc = 9 parts of copper / x kg of copper
Cross-multiplying, you get:
7 * x = 31.5 * 9
Now, solve this equation for x (the weight of copper):
7x = 283.5
x = 283.5 / 7
x ≈ 40.5 kg
Therefore, the weight of copper in the alloy is approximately 40.5 kg.
I think you have a typo.
31:5 kg is not a unit of weight, did you mean 31.5 kg?
If so, then just use a ratio ....
zinc/31.5 = 7/9
9zinc = 220.5
zinc = 220.5/9 = 24.5 kg
notice :
24.5 : 31.5 = 245 : 315 = 7 : 9