Sum of 100 terms of 1,3,5,7 ....... 199 are?

M4maths Previous Puzzles

12 Jul 2010 Find the sum?

Sum of 100 terms of 1,3,5,7 ....... 199 are?

OPtion

1) 9690
2) 8432
3) 9878
4) 8150
5) 10000
6) 9000
7) 11740
8) 12345
9) 7900
10) 10453

Solution

Sum of 1 and 199 = 200
Sum of 3 and 197 = 200
Sum of all the 50 pairs in the sequence = 200 * 50 = 10000

Correct Option: 5 Best Solution (10)

SUDESHNA SEN   14 years AGO

Sum of 100 terms of 1,3,5,7,...,199 i.e. first 100 odd integers is= n^2= 100^2= 10000..... Option 5)

Like? Yes (3) | No   

Prerna   14 years AGO

Sum of AP = n/2 ( a+l) where

n= no of terms;
a=first term;
l= last term

so sum =50*(1+199) =10000

Like? Yes (3) | No   

Dr.Dipin Singh   14 years AGO

Sum of 100 terms of 1,3,5,7 ....... 199 =
100*(1+199)/2=50*200=10000

Like? Yes (2) | No   

Achelal Sharma   14 years AGO

1+3+5+7+...+(2n-1)=n^2;
so
1+3+5+7+...+(200-1)=100^2

Like? Yes (2) | No   

Karan   14 years AGO

sum of AP of 100 terms with first term as 1 and last term 199 = 50*(1+199) = 10000

Like? Yes (2) | No (1)  

Inder Singh Negi   14 years AGO

some of first n odd numbers is n2.

Like? Yes (2) | No (1)  

Pargat Pal Singh   14 years AGO

1+199=200;
3+197=200;
5+195=200;
...
..
97+103;
99+101=200

so there are 50 pairs with sum of 200.

Total sum = 50*200=10000

Like? Yes (1) | No (1)  

Saravanan   14 years AGO

Sum of n terms is=n^2
100^2=10000

Like? Yes (1) | No (1)  

Trishita Dasgupta   14 years AGO

Sum of 100 terms of 1,3,5,7,...,199 i.e. first 100 odd integers is= n^2= 100^2= 10000..... Option 5)

Like? Yes (1) | No (1)  

PADMASHREE   14 years AGO

using n/2(2a*(l-a)/d+1), Thus 100/2(2*1*(199-1)/2+1)= 10000, option (5)

Like? Yes (1) | No (1)