How to solve this ?
Of the 300 subjects who participated in an experiment using virtual-reality therapy to reduce their fear of heights, 40 percent experienced sweaty palms, 30 percent experienced vomiting, and 75 percent experienced dizziness. If all of the subjects experienced at least one of these effects and 35 percent of the subjects experienced exactly two of these effects, how many of the subjects experienced only one of these effects?
(A) 105 (B) 125 (C) 130 (D) 180 (E) 195
Hi Prem,
Kindly following the below points while posting a question.
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- Kindly let us know what is “unclear” in the question and why you are not able to solve. This helps us to answer to the point.
Now lets get back to this question,
I am assuming that you didnt get the question at all,
In that case, remember best way to solve these types of questions are using Venn-Diagram. this is a non- mutually exclusive question type.
Please find below the diagram,
From the diagram,
A+x+y+T = 40
B+x+T+z = 30
C+y+z+T = 75
We have to find A+B+C ?
Adding these three equations we get,
A+B+C+2(x+y+z)+3T = 145 ………. (1)
We know that,
x+y+z = 35
Total = x+y+z+A+B+C+T = 100—–(2)
Substituting in the equation (1 ) we get,
A+B+C+x+y+z+T+ x+y+z+2T = 145
100+ 35+2T = 145
So T = 5
substitute in equation 2, we get
A+B+C = 60
This is for 100 people, then for 300 people it is 180.
So answer has to be D
Hope this is clear.