During the testing of drug the result were found to be 85% positive in the first phase of 100 tests and 55% positive of second phase.If the overall results were 75% positive.what was the total number of tests conducted in first phase and second phase?

• 150
  85+55%ofX=75%of(100+X)
• 7 years agoHelpfull: Yes(22) No(2)
• 85/100*100 (+ve 1st Phase) + 55/100*x (+ve 2nd phase) = 75/100(100+x);
  After Solving we will get x=50;
  Therefore Total will be 100+50 = 150 Ans
• 7 years agoHelpfull: Yes(11) No(0)
• (85/100)*100+(55/100)*x=(75/100)*(100+x)
  x=50
  total=100+x=100+50=150
• 7 years agoHelpfull: Yes(5) No(0)
• let the number of tests conducted in first phase be 'X'. positive % = 85% of X = 0.85X
  let the number of tests conducted in second phase be 'Y'. positive % = 55% of 'Y' = 0.55Y
  total positive % of 1st and 2nd phase = 0.85X + 0.55Y
  total tests conducted in 1st and 2nd phase = X + Y
  0.85X +0.55Y = 75% of (X +Y) = 0.75X + 0.55Y
  0.85X - 0.75 X = 0.75Y -0.55Y
  0.1 X = 0.2 Y
  X / Y = 0.2 / 0.1 = 2
  in 1st phase, tests conducted are 200. positive tests = 85% of 200 = 170
  in 2nd phase, tests conducted are 100. positive tests = 55% of 100 = 55
  total tests in 1st and 2nd phase = 200 + 100 = 300
  total positive tests in 1st and 2nd phase = 170 + 55 = 225
  total % of positive tests = total positive tests/ total number of tests = 225/ 300 = 75%
• 7 years agoHelpfull: Yes(4) No(8)
• 85 55
  75
  20 10
  2:1 ratio
  first phase
  (2/3)*100=66
  second phase
  (1/3)*100=33.3
• 7 years agoHelpfull: Yes(2) No(6)
• 85+x/2=(75/100)*(100+x)
• 7 years agoHelpfull: Yes(0) No(3)
• A=(85/100)*100=85
  B=(55/100)*X
  A+B=(75/100)*(100+X)
  85+ (55/100)*X =((75/100)*100)+((75/100)*X)
  85+ (55/100)*X =75+((75/100)*X)
  85-75=((75/100)*X)-(55/100)*X
  10=(20/100)*X
  X=50
  total number of tests conducted in first phase and second phase=100+X
  I.E(100+500)
  150
• 6 years agoHelpfull: Yes(0) No(1)
• RAJABOINA RADHIKA:::
  they asked 75% of overall results, then y 75/100(1000+x)
• 6 years agoHelpfull: Yes(0) No(0)
• 85/100*100 (+ve 1st Phase) + 55/100*x (+ve 2nd phase) = 75/100(100+x);
  Solving we will get x=50;
  Therefore Total will be 100+50 = 150 Ans
• 6 years agoHelpfull: Yes(0) No(0)
• Let total test in first and second phase is x then:
  [[85/100]*100] + [[55/100]*[x-100]] = [75/100]*x
  8500 + 55x - 5500 = 75x
  3000 = 20x
  x = 150 ANS
• 5 years agoHelpfull: Yes(0) No(0)