Question

how many two digit numbers are divisible by 3

Answer 1

12,15,18.................99

a=12, d=3, an=99

an= a+(n-1)d

99= 12+(n-1)3

99= 12+3n-3

99= 12-3+3n

99=9+3n

90=3n

n= 90/3

n= 30

hope it may help you

Answer 2

Answer:-

The list of two digit numbers divisible by 3 is:

$\small\sf{12,15,18,......99}$

$\large\sf{Here,}$

$\small\sf{a=12}$

$\small\sf{d=3}$

$\small\sf{an=99}$

$\small\sf{an=a+(n-1)d}$

$\small\sf{99=12+(n-1)3}$

$\small\sf{87=(n-1)3}$

$\small\sf{n-1=\frac{87}{3}=29}$

$\small\sf{n=29+1=30}$

So, there are 30 two digit numbers divisible by 3.