Question

sum of all 2 digit numbers​

Answer 1

Answer:

4905

btw I don't know why you want to know this but I hope that it helped

Step-by-step explanation:

10 + 11 + 12 + 13 + 14 + 15 + 16 + 17 + 18 + 19 + 20 + 21 + 22 + 23 +49 + 26 + 27+28+29+30.................................................................................................................................................................................................................................................................................................+98+99=4905

Answer 2

A.P = 10,11,12.............,99

a=10

d=1

n=?

an=99

To find: sum of all two digit numbers

Here, we have

an=a+(n-1)d

99=10+(n-1)1

89=n-1

n=90

now,

Sn=n/2(an+a)

S90=90/2(99+10)

=45(109)

=4905

therefore,sum of all two digit numbers is 4905.