Question

Find the sum of all two digits divisible by 3​

Answer 1

Answer:

some of the numbers are

33

42

63

81

Answer 2

The first two digit number divisible by 3 is 12
The last two digit number divisible by 3 is 99

By arithmetic progression
a=12 d=3
an=a+(n-1)d
99=12+(n-1)3
87=3n-3
90=3n
n=30

Sn=n/2(12+99)
Sn=30/2(111)
=15(111)
=1665

So the sum is 1665