4. Divide the natural number 1-500 into three groups, group A: 1, 6, 7, 12, 13, 18 Group B: 2,5,8 4. Divide natural numbers 1-500 into three groups Group A: 1, 6, 7, 12, 13, 18 Group B: 2, 5, 8, 11, 14, 17 Group C: 3,4,9,10,15,16 Please answer the following questions: 1) how many numbers are in group B? 2) what is the 48th number in group A? 3) which group does 298 belong to

4. Divide the natural number 1-500 into three groups, group A: 1, 6, 7, 12, 13, 18 Group B: 2,5,8 4. Divide natural numbers 1-500 into three groups Group A: 1, 6, 7, 12, 13, 18 Group B: 2, 5, 8, 11, 14, 17 Group C: 3,4,9,10,15,16 Please answer the following questions: 1) how many numbers are in group B? 2) what is the 48th number in group A? 3) which group does 298 belong to

I don't want to tell you the rule. A is to add five first and then one. B is to add three and then one and then five

If n is a natural number and N ≥ 3, it is proved that 2n > 2n + 1

It is proved that: 1) when n = 3, 8 ＞ 7 holds; 2) suppose that n = k, the inequality holds, that is, 2K ＞ 2K + 1; then when n = K + 1, the left side = 2K + 1 ＞ 4K + 2 ＞ 2K + 3 holds. In conclusion, 2n ＞ 2n + 1

Prove inequality 1 + 1 / √ 2 + 1 / √ 3 +. + 1 / √ n

Scaling method
1/√n=2/2√n