แบบฝึกหัด

1. จงหาจำนวนเฉพาะที่อยู่ระหว่าง 1 และ 40
 ...................................................................................................................................................................
 ...................................................................................................................................................................  ...................................................................................................................................................................

2. จงหาจำนวนเฉพาะที่มากที่สุดและน้อยกว่า 80
 ...................................................................................................................................................................

3. 71   91   133   137   และ   149   จำนวนนับใดบ้างเป็นจำนวนเฉพาะ เพราะเหตุใด
 ...................................................................................................................................................................
 ...................................................................................................................................................................  ...................................................................................................................................................................  ...................................................................................................................................................................

4. 3 x  29  เป็นจำนวนเฉพาะหรือไม่ เพราะเหตุใด
 ...................................................................................................................................................................  ...................................................................................................................................................................

5. 87   เป็นจำนวนเฉพาะหรือไม่ เพราะเหตุใด
 ...................................................................................................................................................................  ...................................................................................................................................................................