The marks obtained by Polly and Sandy are in the ratio 4:5 and those obtained by Sandy and Willy are in the ratio of 5:2. The marks obtained by Polly and Willy are in the ratio of...?  Choose the correct choice from the following answers.
A) 2 : 1	B) 3 : 2	C) 4 : 3	D) 5 : 4	E) 6 : 5

Rationale: "polly : sandy = 4 : 5 sandy : willy = 5 : 2 polly : sandy : willy = 4 : 5 : 2 polly : willy = 4 : 2 = 2 : 1 the answer is a ."
Answer: A