Abdul, Mala and Chetan went bird watching. Each of them saw one bird that none of the others did. Each pair saw one bird that the third did not. And one bird was seen by all three. Of the birds Abdul saw, two were yellow. Of the birds Mala saw, three were yellow. Of the birds Chetan saw, four were yellow. How many yellow birds were seen in all? How many non-yellow birds were seen in all?
[SNAP 2008]

(1)7 yellow birds and 3 non yellow birds
(2)5 yellow birds and 2 non yellow birds
(3)4 yellow birds and 2 non yellow birds
(4)3 yellow birds and 2 non yellow birds

Solution:



As per the given information
a = b = c = d = e = f = g= 1
Chetan watched 4 birds and it is given that Chetan watched four yellow birds.

All the birds, he watched are yellow.
c, d, g, f are yellow.

Abdul watched two yellow birds.
a and e are not yellow.

Mala watched three yellow birds.
b is yellow.

There are 5 (b, c, d, g, f) yellow and 2 (a and e) non-yellow birds.
Hence, option 2.