Question

Find the sum of all odd number of 5 digit. which
are divedable by 9​

Answer 1

Answer:

2,75,04,000

Step-by-step explanation:

5 digits odd numbers divisible by 9

the AP is

10017, 10035, 10053 ..... 99999

a = 10017 d = 18 last number = 99999

an = a + (n-1)d

99999 = 10017 + (n-1)18

99999 = 10017 + 18n - 18

99999 = 9999 - 18n

18n = 99999 - 9999

18n = 90000

n = 90000/18

n = 5000

Sn = n/2 (2a + (n-1)d)

= 5000/2 (2(10017) + (5000-1)18)

= 2500 (20034 + 89982)

= 2500 × 110016

= 2,75,04,000

hope you get your answer