Respuesta :

Answer:

1665

Step-by-step explanation:

This is AP, where:

  • First term is: 12= 3*4
  • Last term is: 99= 3*33
  • Common difference is: 3
  • Number of terms is: 33- 3= 30 (because the 4th term is included)
  • S=1/2*30(12+99)= 1665

The sum of all two - digit natural numbers which are divisible by 3 is 1665