CAT 1997 — QA Question 24
Direction: Answer the questions based on the following information.
A survey of 200 people in a community who watched at least one of the three channels — BBC, CNN and DD — showed that 80% of the people watched DD, 22% watched BBC and 15% watched CNN.
Referring to the previous question, what percentage of people watched all the three channels?
Answer & solution
- A
3.5%
- B
0%
- C
8.5%
Cannot be determined
Here, a + b + c + d + e + f + g = 200 ...(i)
80% of the people watch DD implies
c + d + f + g = 160 ...(ii)
22% of the people watch BBC implies
a + d + e + g = 44 ...(iii)
15% of the people watch CNN implies
b + e + f + g = 30 ...(iv)
(ii) + (iii) + (iv) gives
a + b + c + 2(d + e + f) + 3g = 234
Subtracting (i) from this equation,
d + e + f + 2g = 34 ...(v)
From equation (v), we have
(d + 4 + f) + 2g = 34
⇒ (d + f) + 2g = 30
Since we cannot find the values of d and f, the value of g cannot be ascertained.