1000 patients currently suffering from a disease were selected to study the effectiveness of treatment of four types of medicines — A, B, C and D. These patients were first randomly assigned into two groups of equal size, called treatment group and control group. The patients in the control group were not treated with any of these medicines; instead they were given a dummy medicine, called placebo, containing only sugar and starch. The following information is known about the patients in the treatment group.
a. A total of 250 patients were treated with type A medicine and a total of 210 patients were treated with type C medicine.
b. 25 patients were treated with type A medicine only. 20 patients were treated with type C medicine only. 10 patients were treated with type D medicine only.
c. 35 patients were treated with type A and type D medicines only. 20 patients were treated with type A and type B medicines only. 30 patients were treated with type A and type C medicines only. 20 patients were treated with type C and type D medicines only.
d. 100 patients were treated with exactly three types of medicines.
e. 40 patients were treated with medicines of types A, B and C, but not with medicines of type D. 20 patients were treated with medicines of types A, C and D, but not with medicines of type B.
f. 50 patients were given all the four types of medicines. 75 patients were treated with exactly one type of medicine
Question 1:
How many patients were treated with medicine type B?
Show AnswerQuestion 2:
The number of patients who were treated with medicine types B, C and D, but not type A was:
Show AnswerQuestion 3:
How many patients were treated with medicine types B and D only?
Show AnswerQuestion 4:
The number of patients who were treated with medicine type D was:
Show Answer1000 patients are equally distributed into two groups treatment group and control group. We have some information regarding the effectiveness of medicines A, B, C and D on the treatment group. Let us start filling the data give in the restrictions in a four sets Venn diagram.
75 patients were treated exactly one type of medicine.
\(\therefore 25 + x + 20 + 10 = 75\)
\( \Rightarrow x = 20\)
We have only one unknown in type-A medicine. \(220 + b = 250 \Rightarrow b = 30\)
100 patients were treated with exactly three types of medicines. \(40 + 20 + 30 + a = 100\)
\( \Rightarrow a = 10\)
Now, we have only one unknown in each of the type C and type-D.
\( \Rightarrow p = 210 - 190 = 20\)
\( = 500 - 350 = 150\)
Question 1: Answer: 340
Question 2: Answer: 10
Question 3: Answer: 150
Question 4: Answer: 325
CAT 2020 LRDI sets with Solutions
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