Question

Sum of the integers from 1 to 100 which are divisible by both 3 and 5

Answer 1

Answer:

there are 20 numbers divisible by 5 and 33 numbers divisible by 3 so the total numbers which are divisible by both 3 and 5 between 1 to 100 are 20+33=53 numbers.

so 53 numbers are there which are divisible by both by 3 and 5 and the numbers are between 1 to 100.

Step-by-step explanation:

hope you are satisfied with the answer and if yes then don't forget to give it the heart and vote it....

Answer 2

Answer:

315

Step-by-step explanation:

Integers which are divisible by 3 and 5 [ we can take it as 3 × 5 = 15] and which lie from 1 to 100 are,

15, 30, 45, ......... , 90

First, let us find the number of terms, i.e., n,

$a_{n}$ = a + (n - 1)d

$a_{n}$ = 15 + (n - 1)15

90 - 15 = (n - 1)15

75 = (n - 1)15

n - 1 = 5

n = 6

Now, we will find the sum, i.e., $S_{n}$,

$S_{n}$ = n/2(a + l)

$S_{n}$ = 6/2(15 + 90)

$S_{n}$ = 3(105)

$S_{n}$ = 315 [answer]

Hope this helps you!!!