Mathematics for IGCSE & O level - Number (Section 1 - No. 29)
What are the first four prime numbers?
1, 2, 3, 5
2, 3, 5, 7
0, 2, 3, 5
2, 4, 6, 8
解释
Prime numbers are numbers that have exactly two factors, 1 and itself. The first four are 2, 3, 5, and 7.