Question

The sum of all numbers between

I and looo
which aredivisible by 3

​

Answer 1

Answer:

How many numbers from 1 to 1000 is divisible by 3?

Let’s break the range into one, two and three digit numbers respectively.

1 - 9 -> 3 , 6 , 9 => Three nos in this range = 3

10 - 99 -> 12, 15, 18 …..,99 => Thirty nos in this range { we can get the value of n by using the nth term formula i.e [a + (n-1) * d] } = 30

100–999 -> 102,105,…..,999 => Three hundred nos in this range = 300

We are left out with 1000 and we can make out that it is not divisible by 3.

Hence, total numbers between 1 and 1000 divisible by 3 = 3 + 30 + 300 = 333.

333 is your answer.

Step-by-step explanation:

Answer 2

It’s AP
Where
a = 3
d = 3
Last term L= 999

999 = 3 + ( n-1 ) 3
999 = 3 n
n = 333

Sum AP = n/2 ( a + L)= 333/2 ( 3 + 999)
= 333 + 501
= 834