Latest Infosys Aptitude Question SOLUTION: 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 w

• Placement Papers
• /
• Infosys
• /
• Numerical Ability
• /
• Percentage

Infosys Question Papers: Infosys Interview Experience(10) INFOSYS Company Profile

(#M40164657) INFOSYS Numerical Ability question Percentages Keep an EYE

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?

Asked In Infosys Ranjitha Kulakdhaniya (6 years ago)

Unsolved Read Solution (10)

Is this Puzzle helpful?   (44)   (21) Submit Your Solution Percentage

Read Solution (10) :

Sreejita Gupta  (6 years ago)

150
85+55%ofX=75%of(100+X)

Is this solution Helpfull? Yes (22) | No (2)  

Prasun Jaiswal  (6 years ago)

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

Is this solution Helpfull? Yes (11) | No   

Rajaboina Radhika  (6 years ago)

(85/100)*100+(55/100)*x=(75/100)*(100+x)
x=50
total=100+x=100+50=150

Is this solution Helpfull? Yes (5) | No   

M J SHIVAYOGI  (6 years ago)

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%

Is this solution Helpfull? Yes (4) | No (8)  

Niharia  (6 years ago)

85 55
75
20 10
2:1 ratio
first phase
(2/3)*100=66
second phase
(1/3)*100=33.3

Is this solution Helpfull? Yes (2) | No (6)  

Chandra Shekhr Suyal  (6 years ago)

85+x/2=(75/100)*(100+x)

Is this solution Helpfull? Yes | No (3)  

mahendra babu  (5 years ago)

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

Is this solution Helpfull? Yes | No (1)  

sai kiran L  (5 years ago)

RAJABOINA RADHIKA:::
they asked 75% of overall results, then y 75/100(1000+x)

Is this solution Helpfull? Yes | No   

Abhishek  (5 years ago)

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

Is this solution Helpfull? Yes | No   

Rohan Bar  (4 years ago)

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

Is this solution Helpfull? Yes | No   

Please Login to Read Solution.