Q13 of 202 Page 9

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

(ii) 100 and 200

(i) 0 and 50

a = 1, l = 49, n = 25

S₂₅= [a + l]

= [1 + 49]

= (50) = 625

(ii) 100 and 200

a = 101, l = 199, n = 50

S₅₀= [a + l]

= 25 (101 + 199)

= 25 (300) = 7500

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