Find the sum of all odd numbers between (i) 0 and 50 (ii) 100 and 20

1.	Find the sum of all odd numbers between (i) 0 and 50 (ii) 100 and 200
Answer» (i) 0 and 50 a = 1, l = 49, n = 25 S_{25 = \(\cfrac{25}{2}[a + l]\)} =_{\(\cfrac{25}{2}[1 + 49]\)} \(\frac{25}{2} (50) = 625\) (ii) 100 and 200 a = 101, l = 199, n = 50 S₅₀ = _{\(\cfrac{50}{2}[a + l]\)} = 25 (101 + 199) = 25 (300) = 7500

Find the sum of all odd numbers between (i) 0 and 50 (ii) 100 and 200

Answer»

(i) 0 and 50

a = 1, l = 49, n = 25

S_{25 = \(\cfrac{25}{2}[a + l]\)}

=_{\(\cfrac{25}{2}[1 + 49]\)}

\(\frac{25}{2} (50) = 625\)

(ii) 100 and 200 a = 101,

l = 199, n = 50

S₅₀ = _{\(\cfrac{50}{2}[a + l]\)}

= 25 (101 + 199)

= 25 (300) = 7500