Information :

1. AB = 8
2. CD = 7
3. O,B,D are centers of the respective circles

Hint: Find hidden information/clue from the diagram to solve the puzzle.

Note: diagram is not to scale; it is just for visual reference.

P.S: the signature in the bottom right is mine and used for my own puzzles.

• reason for my downvote: circle 1 being bigger than circle 2 (and 3) is an important fact to get a single correct answer (3,2,1). You saying that the diagram is not to scale means that it is not guaranteed to be the case. so 2,4,3 and 1,5,4 could als be correct answers for the radiuses of circle one two and three respectively. – Ivo Beckers Jan 6 '17 at 14:01
• @Ivo Beckers ...diagram is not to scale means that its not drawn as per radius, however since puzzle can be solved by considering important fact that 1 > 2 > 3 hence its drawn in proportion to depict the fact, which can be found by inspection of proportion only. Hence, it is having comprehensive information to solve – Dharmesh Jan 6 '17 at 14:36
• I disagree. If it was drawn in proportion then circle 2 should be double the radius of circle 3 or at least approximately – Ivo Beckers Jan 6 '17 at 14:40
• proportion to show only 1 > 2 > 3 If we see 2 and 3 have only slight difference since they have a minor difference and 1 is bigger than both – Dharmesh Jan 6 '17 at 14:45

All we know from the information provided in the question is that

the radius of circle 2 is one greater than the radius of circle 3 (since when adding the diameter of circle 1 to these two quantities, we get the lengths AB=8 and CD=7).

Let $R_1,R_2,R_3$ be the radii of the respective circles 1,2,3. We have:

• $2R_1+R_2=8$
• $2R_1+R_3=7$
• $R_1,R_2,R_3\in\mathbb{N}$
• $R_1>R_2>R_3$ (by inspection)

So the only possibility is:

$R_1=3,R_2=2,R_3=1$.