49
666 integers.
There are 44 positive integers less than 2,010 that have an odd number of factors.
There are 130 positive integers less than 1,000 that are divisible by seven but not divisible by 11
There are 544 positive integers less than 1,000 that are either divisible by two or by 11.
There are 80 such integers.
49
666 integers.
There are 44 positive integers less than 2,010 that have an odd number of factors.
There are 130 positive integers less than 1,000 that are divisible by seven but not divisible by 11
There are 544 positive integers less than 1,000 that are either divisible by two or by 11.
Eight.
6
One less than 10000.
The squares -- nine of them.
7 of them.
There are 1,963 such integers. Every factor of a number has a pair. The only time there will be an odd number of factors is if one factor is repeated, ie the number is a perfect square. So the question is really asking: how many positive integers less than 2008 (in the range 1 to 2007) are not perfect squares. √2007 = 44 and a bit (it lies between 44 and 45) So there are 44 integers less than (or equal to) 2007 which are perfect squares → 2007 - 44 = 1963 integers are not perfect squares in the range 1-2007 and have an even number of factors (divisors).