Prime Numbers between 1 and 150
Date: 7/30/96 at 20:38:31 From: SunjayMishra Subject: Number of Prime Numbers Hello, On a recent test, there were problems concerning prime numbers. Although I understand them, the questions asked, "How many prime numbers are there between 1 and 150?" Is there any formula to figure this out? Jay
Date: 7/31/96 at 4:2:44 From: Doctor Pete Subject: Re: Number of Prime Numbers Hello, There is no simple way to count the exact number of primes between two given numbers except by sieving (i.e., writing out all the numbers between 1 and 150, then crossing out multiples of 2, 3, 5, etc). I think this question was unoriginal, biased, and not indicative of the solver's mathematical ability, because it basically amounts to memorization and computation (there are 25 primes between 1 and 100, something that could easily be memorized, and the numbers between 100 and 150 can be counted). -Doctor Pete, The Math Forum Check out our web site! http://mathforum.org/dr.math/
Search the Dr. Math Library:
Ask Dr. MathTM
© 1994- The Math Forum at NCTM. All rights reserved.