sheikhaamir wrote:

can someone plz. explain the solution of this question by the method of venn diagram....

See the attached diagram: I denotes intelligent aliens, and m3 denotes those with more than 3 arms.

Among those who don't have more than 3 arms, the ratio between those who are intelligent and those who aren't is 75:25, therefore 3x and x in the diagram.

Knowing that 3x + 10 = 40, it follows that x =10, and from the diagram, those who have more than 3 arms is 100 - 30 - 10 = 60.

Answer: 60%.

Attachments

Aliens-Venn.jpg [ 17.82 KiB | Viewed 1433 times ]

_________________

PhD in Applied Mathematics

Love GMAT Quant questions and running.