An alloy contains magnesium, copper and zinc in the ratio 3 : 4 : 2 and another alloy contains coppe

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10 May 2022 Ratio & Proportion

An alloy contains magnesium, copper and zinc in the ratio 3 : 4 : 2 and another alloy contains copper, zinc and nickel in the ratio 4 : 5 : 3. If equal weights of both alloys are melted together to form a third alloy, then the weight of copper per kg in new alloy will be:

OPtion

1) 175 gm
2) 225 gm
3) 125 gm
4) 319.44 gm
5) 388.88 gm
6) 416.66 gm
7) 166.66 gm
8) 305.55 gm
9) 527.77 gm
10) None of these

Solution

In 1st alloy: Ratio of magnesium, copper, Zinc = 3 : 4 : 2
In 2nd alloy: Ratio of copper, zinc, nickel = 4 : 5 : 3
Now, let the weight of first alloy be 36 kg (taken as Magnesium=12 kg, Copper=16 kg, Zinc=8 kg) and
Weight of second alloy = 36 kg (taken as Copper=12 kg, Zinc=15 kg, Nickel=9 kg)
When two alloys are mixed in equal weights, total weight of third alloy=36+36=72 kg
Weights in 3rd alloy: Magnesium=12 kg, Copper=(16+12) kg, Zinc=(8+15) kg, Nickel=9 kg.
Weight of Copper in 3rd alloy = 28 kg per 72 kg
.'. Weight per kg = 28/72 kg = 388.88 gm..

Correct Option: 5 Best Solution (2)

G.S.Kantharao   1 year AGO

Magnesium:copper:zinc=3:4:2
Copper:zinc:nickel=4:5:3

Now, let the first alloy be 36kg =3:4:2=(3+4+2)=9×4=12:16:8=36kg

Now second alloy be 36kg= 4:5:3=(4+5+3)=12×3=12:15:9=36kg
Now Alloys are mixed together to form third alloy. Then the ratio of content in it,
Magnesium:copper:zinc:nickel =12:28:23:9
Now third alloy weight is 36+36=72kg
Now copper weight=28/72=388.88gms
So my option is 5

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Pargat Pal Singh   1 year AGO

If 36 kg of each alloy are mixed, then quantity of copper in final 72 kg product = 16+12=28 kg
Qnty of copper in 1 kg=28/72=0.388888 kg means 388.88 gms

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