You need a 18% acid solution for a certain test, but your supplier only ships a 13% solution and a 43% solution. You need 120 lts of the 18% acid solution. the 13% solution costs Rs 82 per ltr for the first 67 ltrs, and Rs 66 per ltr for any amount in access of 67 ltrs. What is the cost of the 13% solution you should buy?

(a) 8002 (b) 7012 (c) 7672 (d) 7342

• first we need to find out the ratio in which 13% solution and 43% solution are mixed. Let them be x and y.
  So, 0.13x+0.43y=0.18(x+y)
  this gives x/y=5/1,
  So, to make 120 litres we need 5 volumes of 13% solution and 1 volume of 43% solution. 5a+1a=120, so a=20.
  This means we need 20*5=100 litres of 13% solution.
  
  So cost=82*67+(66*(100-67))
  => 82*67+66*33= 7672
  
• 9 years agoHelpfull: Yes(19) No(0)
• total he needs 120 litres
  so 67*82=5494
  and(120-67=33)=>33*66=2178 total=7672
  
• 9 years agoHelpfull: Yes(8) No(16)
• By allegation acid should be mixed in the ratio of 5:1 therefore for 120 litres of 18% soln 100 litres of 13% soln is needed therefore 67*82+33*66=7672
• 9 years agoHelpfull: Yes(4) No(0)
• 13 43
  18
  25 5
  25:5=5:1
  120 devides into 5:1 ratio
  hence 100L of 13%,20L of 43%
  so cp=82*67+66*33=7672
• 9 years agoHelpfull: Yes(1) No(0)
• 67*82=5494
  120-67=53*66=3498
  total is 8992 ??????
• 9 years agoHelpfull: Yes(0) No(3)