two alloys contain zinc and copper in the ratio of 2:1 and 4:1. in what ratio the two alloys should be added together to get as new alloy having zinc and copper in the ratio of 3:1?

• friends ques posted by ratna. . are not the qs. asked in tcs. do not waste ur tym wid those :)
• 12 years agoHelpfull: Yes(15) No(4)
• two alloys should be added in the ratio of 3:5
  let total weight is 30 gm.
  in alloy1: zinc=20 cu=10
  alloy2: zinc=24 cu=6
  if we mix 30% of alloy1 & 50 % of alloy2 we will get new alloy containing zinc=18 & cu=6 which gives required ratio 3:5 of two alloys
  
• 12 years agoHelpfull: Yes(10) No(7)
• both alloy should be added in 10:17 ratio
  
• 12 years agoHelpfull: Yes(1) No(6)
• first take the lcm of (2+1)=3 and (4+1)=5 , which is 15.
  in 1st alloy zinc=(15/3)*2=10 and copper=(15/3)*1=5
  similarly in 2nd zinc=12 and copper=3
  now let take x from 1st and y from 2nd.
  according to question
  {(x/15)*10+(y/15)*12}/{(x/15)*5+(y/15)*3}=3/1
  (10x+12y)/(5x+3y)=3/1
  10x+12y=15x+9y
  5x=3y
  x/y=3/5
  ans-3/5
• 9 years agoHelpfull: Yes(1) No(2)
• Let the ratio in which they are mixed is x:y
  then,
  [(2/3)x+(4/5)y]/[(1/3)x+(1/5)y]=3/1
  or, 10x+15y=15x+9y
  or, 6y=5x
  0r x/y=6/5
  Hence the ratio is 6:5
• 6 years agoHelpfull: Yes(0) No(0)