If an alloy consist of 30% copper, 40% zinc and the remaining is nickel. Then the amount of a Nickel in 20 kg of alloy is

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question is not completed ie copper is how many %
A and B together can do a piece of work in 8 days, but A alone can do it in 12 days. B alone would complete the work in ......days
A can finish work in 1/12 day, and A ans B together  in 1/8 days 
So, 1/B = 1/A&B - 1/A = 1/8 - 1/12 = 1/24, So B Complete the work in 24 days

Answers

2016-02-22T15:18:40+05:30
6 kg is the answer........................................
0
2016-02-23T15:42:49+05:30
Let the total amount of alloy = 100%
copper = 30%   
zinc = 40%
then Nickel = 100-(30+40)
                    = 100 - 70 = 30
the amount of nickel in the  alloy = 30/100 * 20= 6 kg
                              
                             also copper is = 30/100 * 20 =  6 Kg
                                         Zinc       = 40/100*20 =   8 kg                        
 
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