00:01
So here the question is asked to find the number of positive integers that is less than thousand and those are multiples of three, five or seven.
00:09
So the total number we have to find three, five or seven.
00:13
This is not the multiple of three and five and seven.
00:16
This is multiples of three or multiples of five or multiples of seven, which means multiples of three plus multiples of five plus multiples of seven.
00:24
Now, i can write the multiples of 3 as multiples of 3.
00:35
I'm just marking that with set a maybe.
00:38
So, multiples of 3 will be in set a, that is 3, 6, 9, 12, 15, 18, 21, etc.
00:50
Of course, i'm not going to write all the multiples of 3 up to 1 ,000.
00:53
So up to 1 ,000, it will be going.
00:56
So this will be the set of elements here.
00:59
Now, next thing is multiples of multiples of 5.
01:08
So i'm just marking that as set b.
01:11
So that i can write it as 5, 10, 15, 20, 25, etc...