Question

Find the sum of the odd numbers between 0 and 50.

Answer 1

Odd numbers between 0 and 50 are
1,3,5,.........,49
a=1,an=49,d=3-1=2
we know
an=a+n-1×d
49=1+n-1×2
n-1×2=49-1
n-1×2=48
n-1=48/2
n-1=24
n=24+1
n=25
Sn=n/2(2a+n-1×d)
S25=25/2(2×1+25-1×2)
=25/2(2+24×2)
=25/2(2+48)
=25/2(50)
=25×25
=625
S25=625

Answer 2

$<b>$ hey mate

here's your answer,

1st term = a=1

last term = l =49

total odd numbers = 25

n = 25


》$\frac{n}{2}$

》$\frac{25}{2}$

》$\frac{25}{2}$ × 50

》 625

$\huge\boxed{625}$