Question

Find the sum of all natural numbers divisible by 3 and less than 31​

Answer 1

Answer:

HOLA MATE ,  UR ANSWER IS  165

Step-by-step explanation:

THE AP FORMED IS AS FOLLOWS

3,6,9,12....30

so by AP formula

an = a + ( n - 1 )d

30 = 3 + 3n -3

3n = 30 , n = 30/3 = 10

therefore the number of terms are 10

by the formula of the sum of AP

Sn = n/2 ( a + l )

Sn = 10/2 ( 3 + 30 )

therefore Sn = 5  X 33 = 165