Find the sum of all odd numbers between 5 and 205101, Sn-[Hints : 5, 7

1.	Find the sum of all odd numbers between 5 and 205101, Sn-[Hints : 5, 7, 9, 11,10605], 203, 205) n
Answer» It is an AP with a = 5 and d = 2. Tₙ = 205 = a+(n-1)d = 5 +(n-1)2 200/2 = 100 = n-1, or n = 101. S₁₀₁ = (101/2)[25+ (101–1)2] = (101/2)[10+200] = 101210/2 = 10605. Answer: The sum of odd numbers from 5 to 205 is 10605.

Find the sum of all odd numbers between 5 and 205101, Sn-[Hints : 5, 7, 9, 11,10605], 203, 205) n

Answer»

It is an AP with a = 5 and d = 2.

Tₙ = 205 = a+(n-1)d = 5 +(n-1)*2

200/2 = 100 = n-1, or n = 101.

S₁₀₁ = (101/2)[2*5+ (101–1)*2]

= (101/2)[10+200]

= 101*210/2

= 10605.

Answer: The sum of odd numbers from 5 to 205 is 10605.