Question

What is the sum of numbers between 300 and 400 divide 6 9 12

Answer 1

here the logic is that the numbers that divide 6 9 and 12 will be divisible by 3 also .

a1 = 306

an=396

no. of terms = [ (396-306)/6] +1

= 16 terms.

Sum= 16/2(306+396)

=5616