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There are two alloys of gold and silver. In the first alloy there is twice as much as gold as silver,and in second alloy there is 5 times less gold than silver.
How many times more must we take of the second alloy than the first in order to obtain a new alloy in which there would be twice as much silver as gold
A1: S = x , G=2x
A2: S=6y, G=y
Taking 'a' quantities of A1 and 'b' quantities of A2.
A3: ax+6yb=2(2ax+yb)
a/b= 3x/4y
Since we do not know amount of Gold and Silver in A1 and A2. I don't think we'll be able to answer any better.
G S
A1 - 1 : 2 = 2kg + 4kg {let both alloy 6 kg }
A2 -. 5 : 1 = 5kg + 1 kg
We need new alloy - 1:2
If we add one A1 and one A2 gold and silver would be 5kg and 7 kg but 5:7 ≠ 1:2
if we add one A1 and two A2
Gold = 4 + 1+1 = 6 kg
Silver = 2+5+5 = 12 kg
6kg : 12 kg ~ 1 : 2. So we must to take two tims more of the second alloy than the first.
Two times ,, Ans.
Practice more questions on quant from Cracku CAT Quotient. Also Download Mixtures and Alligations formulas for CAT, which covers concepts and formulas on this topic.
