TCS
Company
Logical Reasoning
Number Series
Find the sum of even divisors of 4096.
Read Solution (Total 14)
-
- 4096 = 2^12
sum of even divisors = 2^1+2^2+2^3+...+2^12 = (2^13-2) - 10 years agoHelpfull: Yes(28) No(2)
- 2^1+2^2+2^4......+2^12
the series is in geometric series....
so the sum of g.m=a(r^n-1)/(r-1)
a=first term
r=common ratio..
n=12
since 4096=2^12
a=2
r=4
ans=2^13-2 - 10 years agoHelpfull: Yes(7) No(6)
- first find out the divisors or factors of 4096 by taking LCM then all the factors like 2^12 then it will be written (2^0+2^1+2^2...+2^12)but when we have to find even divisors then eliminating 2^0 from above expression and sum up all the values and get ans as 8190.....
- 10 years agoHelpfull: Yes(6) No(0)
- rakesh plz explain
- 10 years agoHelpfull: Yes(2) No(1)
- sum of even divisors = 2^1+2^2+2^3+...+2^12 = 2^12
by using sum of Gp - 10 years agoHelpfull: Yes(2) No(2)
- 8190
except 2^0(even divisors)
2^1+.......+2^12 - 10 years agoHelpfull: Yes(1) No(1)
- 2^12=4096
13 ans
- 10 years agoHelpfull: Yes(1) No(3)
- 4096/19=215
- 10 years agoHelpfull: Yes(0) No(6)
- it is a G.P.
2,4,8,16,32....4096
sum of G.P. is 4094=2^12-2
- 10 years agoHelpfull: Yes(0) No(1)
- Its factors are 2,4,8,16,32,64,128,256,512,1024,2048,4096. Howi calculated this?? firstly we have to find out the factors till half of the square divisor of 4096. Since 60*60=3600 and 70*70=4900 so we have to find factors till 60-70. So i started calculating from 2,2*2048, 4*1024, 8*512 since these all are factors in the form of powers of 2, i calculated all the factors by simple guessing.
- 10 years agoHelpfull: Yes(0) No(1)
- 4096=2^12
even divisors are 2,4,8,16,32,64,128,256,512,1024,2048
i.e. 2^1,2^2,2^3,2^4,2^5,2^6,2^7,2^8,2^9,2^10,2^11
the sum of these numbers is: (2^12)-2 =4094 - 10 years agoHelpfull: Yes(0) No(2)
- the factors are 2^0,2^1,2^2,.....,2^12
so sum o the factors will be 2^13-2
- 10 years agoHelpfull: Yes(0) No(2)
- what is the remainder when 48^565 divided by 7? todays my tcs question
- 10 years agoHelpfull: Yes(0) No(1)
- 4096=2^12
so total number of factors will be 12+1=13
so sum=2^13-2 - 9 years agoHelpfull: Yes(0) No(1)
TCS Other Question