Question

Find the sum of all odd positive integers less than 450 in A.p

Answer 1

Answer:

61875

Step-by-step explanation:

A/C to the question,

here a = 1 , d = 2 , l = 449

therefore,

l = a + (n-1)d

449 = 1 +(n-1)2

224 = n -1

n = 225.

hence ,

Sn = n / 2 (a + l)

Sn = 225 /2 (550)

Sn = 61875

Answer 2

Step-by-step explanation:

we know that first odd +ve integer is 1.and common difference is 2.

so,a=1,d=2,last term(l)=449.

l=a +(n-1)d

449=1+(n-1)(2)

449-1=(n-1)(2)

448÷2=n-1

224=n-1

225=n

putting n=225 in sum of n terms of A.P that is (n/2){2a+(n-1)d}