SOLUTION: How many integers, 1 to 1000, inclusive, are divisible by neither 2 nor 5?

Algebra.Com
Question 251902: How many integers, 1 to 1000, inclusive, are divisible by neither 2 nor 5?
Answer by solver91311(24713)   (Show Source): You can put this solution on YOUR website!


Even numbers are divisible by 2, odd numbers are not. Of the numbers 1 to 1000, half of them are odd, so half of them are not divisible by 2.

Numbers that end in either 5 or 0 are divisible by 5. Of the 500 odd numbers in the range 1 to 1000, none of them end in 0 because any number that ends in 0 is even. All 500 of those odd numbers end in 1, 3, 5, 7, or 9, evenly distributed, so one-fifth of them end in 5.

That means that 4/5 of the 500 odd numbers is not divisible by either 2 or 5.


John


RELATED QUESTIONS

how many integers between 1 and 2012,inclusive, are divisible by neither 3 nor... (answered by Edwin McCravy)
How many positive integers not exceeding 3278 are divisible by neither 12 nor 15? (answered by Fombitz,Edwin McCravy)
How many integers from 1 to 1000 inclusive are multiples of 2 or multiples of... (answered by vleith)
How many integers from -3000 to 3000, inclusive, are divisible by... (answered by edjones)
How many integers from - 3000 to 3000 inclusive are divisible by 3... (answered by Fombitz)
how many positive integers not exceeding 1000 are divisible by 3?,by 5?,by 3or 5? (answered by Fombitz,meldocallos)
The sum of all the natural numbers from 200 to 600 (both inclusive), which are neither... (answered by ikleyn)
How many numbers between 1 and 100 (inclusive) are divisible by 5 or 8? (answered by Edwin McCravy)
Here Are Two Problems I Am Having Trouble With: 1. How many integers greater than 5... (answered by solver91311)