Question

Find the sum of all two digit natural number which are multiple of 4.

Answer 1

Answer:

IT IS ∞

WE CANNOT COUNT

DIE

GO TO GOD

ASK HIM

Answer 2

Answer:

10,11,12,.....,99 are two digit natural numbers

12, 16,20 ,.....96 are two digit numbers which are divisible by 4

12 ,16, 20 ,....,96 are in AP

first term = a=12

common difference =d = a2-a1 = 16-12 =4

last term = a+(n-1)d= 96

12+(n-1)4= 96

(n-1)4= 96-12

(n-1)4 =84

(n-1)=84/4

n-1=21

n=21+1

n=22

a=4 , d=4 , n= 22

sn =n/2[2a+(n-1)d]

= 22/2[2*4+(22-1)4]

= 11[8+21*4]