1.3的倍数:3.6.9.12.15.18.21.24.27.30.33.36.39.42.45.48.51.54.57.60.63.66.69.72.75.78.81.84.87.90.93.96.99。共33个。
2.5的倍数:5.10.15.20.25.30.35.40.45.50.55.60.65.70.75.80.85.90.95.100。共20个。
3.3*5=15的倍数:15.30.45.60.75.90。共6个。
100-(33+20-6)=53
一共53个
1到100里3的倍数有3,6,9,12,,15,18,21,24,27,30,33,36,39,42,45,48,51,54,57,60,63,66,69,72,75,78,81,84,87,90,93,96,99共33个,5的倍数有5,10,15,20,25,30,35,40,45,50,55,60,65,70,75,80,85,90,95,100共20个,既是3的倍数又是5的倍数有15,30,45,60,75,90共6个那么
1到100既不是3的倍数又不是5的倍数的数一共有100-33-20+6=53个。
既不是3的倍数又不是5的倍数的数有53个