Sieve formula

#IE#sieve#formula

Statement

State and apply the sieve formula to count numbers up to $100$ coprime to $30$ .

Hint

Count numbers not divisible by $2$ , $3$ , $5$ .

Show solutionHide solution

From earlier. Numbers divisible by $2$ , $3$ , or $5$ : $74$ .

Complement. $100-74=26$ .

Conclusion. $26$ coprime to $30$ .