# Logical Reasoning - Number Series - Discussion

### Discussion :: Number Series - Type 4 (Q.No.1)

Find the number that fits somewhere into the middle of the series. Some of the items involve both numbers and letters

1.

Look at this series: F2, __, D8, C16, B32, ... What number should fill the blank?

 [A]. A16 [B]. G4 [C]. E4 [D]. E3

Explanation:

The letters decrease by 1; the numbers are multiplied by 2.

 Vinod said: (Jul 6, 2011) (from the backwards) letters are in reverse order, and numbers are divided by 2.

 Sridhar Pradhani said: (Aug 25, 2011) Yes, letters are in reverse from right to left and numbers are multiplyed by 2 from left to right.

 Tamil said: (Mar 31, 2012) First number is 2 after one space then each number multiply 2, next letter are arrange backward after get answer.

 Yamini said: (Sep 27, 2012) Letters are decreasing order (from left to right) and numbers are divided by 2 (from right to left).

 Rashmi said: (Sep 27, 2014) Letter are in reverse order and numbers are divided by 2.

 Sanjay said: (Oct 26, 2014) Letters are decreasing by one place, at the same time the numbers are increasing by multiplication of 2 to previous number.

 Priyanka Rout said: (Dec 31, 2014) B, C, D, E, F. F, E, D, C, B. 2*1 = 2. 2*2 = 4. 4*2 = 8. 8*2 = 16. 16*2 = 32.

 Sushree said: (Nov 16, 2017) Thank you @Priyanka Ji.

 Kanika said: (May 16, 2018) B, C, D, E, F. F, E, D, C, B. F2, E4, D8, C16, B32. 2*2 = 4, 2*4 = 8, 2*8 = 16, 2*16 = 32.

 Jyothi Reddy said: (Aug 10, 2018) Thanks for explaining the answer.

 Biju said: (Aug 24, 2018) How come 4?

 Hannah said: (Jun 15, 2020) Seeing the pattern here does not require you looking at the letters just the numbers will do. 2,_, 8, 16, 32. The answer would be 4 because all of these numbers are multiples of 2. 8x2= 16, 16x2= 32 so, 2x2= 4. Looking at the pattern with the numbers is way easier the other letters might throw you off. I will explain the lettering, each letter decreases by 1, F, _, D, C, B. They are all going down one. A, B, C, D, E, F! E is before the F and after D, so the final answer would be E4.

 Sanamdep Singh said: (Aug 31, 2021) @Biju. Because they all are multiples of 2, here, in this series, only 4 is missing. So it will be E4.