Q15 of 202 Page 9

Find the sum of all integers between 84 and 719, which are multiples of 5.

a = 85, d = 5, l = 715

n = + 1

= + 1

= = 127

S₁₂₇= (a + l)

= (85 + 715)

= (800) = 50800

Find the sum of all odd numbers between

(i) 0 and 50

(ii) 100 and 200

Show that the sum of all odd integers between 1 and 1000 which are divisible by 3 is 83667.

Find the sum of all integers between 50 and 500, which are multiples of 7.

Find the sum of all even integers between 101 and 999.