Question

what is the sum of the odd numbers 1-50?

Answer 1

Answer:

625

Step-by-step explanation:

sum of all odd no. =Sn

(an=49 , a=1,d=2

so, an=a+(n-1)d

49=1+(2n-2)

49+1=2n

50/2=n

n=25)

Sn=n/2{2a+(n-1)d}

Sn=25/2{2*1+(50-2)}

Sn=25/2{2+50-2}

Sn=25/2{50}

Sn=25*25

Sn=625

hope this answer useful to you

Answer 2

The sum of odd number is:-

S=1+3+5+7+...........+49

a=1

d=2

nth term = a+(n-1)d

49 = 1+(n-1)2

48 = 2n-2

S=[(n/2)2a+(n-1)d]

S=(25/2)(2+48)

S=625...answer

hope it helpful