Brain teaser # 7

Prateek Agarwal (Sr. Executive - Finance & Accounts) (1732 Points)

19 June 2012

Find the Next Number in the series!

1, 3, 7, 15, 31, 63, 127, _____

Give explanation to your answers!

Cheers!!!!!

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4 Replies

RaGHuRaM (The Easy are never Good and the Good are never Easy....) (4952 Points)
Replied 19 June 2012

Answer is 255......

Explanation:

1x2 + 1 = 3

3x2 + 1 = 7

7x2 + 1 = 15

127x2 + 1 = 255.......

(Guest)

255

series	difference between next term
1
3	2	gets double
7	4	gets double
15	8	gets double
31	16	gets double
63	32	gets double
127	64	gets double
255	128	gets double

CA Lokesh Kumar Tiwari (Asst. Finance Manager) (195 Points)
Replied 19 June 2012

255

series differences get doubled in every step.

Prateek Agarwal (Sr. Executive - Finance & Accounts) (1732 Points)
Replied 20 June 2012

Hey Guys....You all got it correct !!

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