Q16 of 202 Page 9

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

a = 56, d = 7, l = 497

n = + 1

= + 1

= + 1 =

= 64

S₆₄= (a + l)

= 32 (56 + 497)

= 32 (553) = 17696

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 84 and 719, which are multiples of 5.

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

Find the sum of all integers between 100 and 550, which are multiples of 9.