2,1,3,5的24点答案：
1:(2 + 1) × (3 + 5)
2:(2 + 1 + 5) × 3
3:((2 + 1) + 5) × 3
4:(2 + (1 + 5)) × 3
5:(2 + 1) × (5 + 3)
6:(2 + 3) × 5 - 1
7:((2 + 3) × 5) - 1
8:2 × (3 × (5 - 1))
9:2 × 3 ×(5 - 1)
10:(2 × 3) × (5 - 1)
11:(2 + 5 + 1) × 3
12:((2 + 5) + 1) × 3
13:(2 + (5 + 1)) × 3
14:(2 × (5 - 1)) × 3
15:2 × (5 - 1) × 3
16:2 × ((5 - 1) × 3)
17:(1 + 2) × (3 + 5)
18:(1 + 2 + 5) × 3
19:((1 + 2) + 5) × 3
20:(1 + (2 + 5)) × 3
21:(1 + 2) × (5 + 3)
22:(1 + 5 + 2) × 3
23:((1 + 5) + 2) × 3
24:(1 + (5 + 2)) × 3
25:3 × (2 + 1 + 5)
26:3 × ((2 + 1) + 5)
27:3 × (2 + (1 + 5))
28:(3 + 2) × 5 - 1
29:((3 + 2) × 5) - 1
30:3 × (2 + 5 + 1)
31:3 × ((2 + 5) + 1)
32:3 × (2 + (5 + 1))
33:3 × (2 × (5 - 1))
34:3 × 2 ×(5 - 1)
35:(3 × 2) × (5 - 1)
36:3 × (1 + 2 + 5)
37:3 × ((1 + 2) + 5)
38:3 × (1 + (2 + 5))
39:3 × (1 + 5 + 2)
40:3 × ((1 + 5) + 2)
41:3 × (1 + (5 + 2))
42:(3 + 5) × (2 + 1)
43:3 × (5 + 2 + 1)
44:3 × ((5 + 2) + 1)
45:3 × (5 + (2 + 1))
46:(3 + 5) × (1 + 2)
47:3 × (5 + 1 + 2)
48:3 × ((5 + 1) + 2)
49:3 × (5 + (1 + 2))
50:(3 × (5 - 1)) × 2
51:3 × (5 - 1) × 2
52:3 × ((5 - 1) × 2)
53:(5 + 2 + 1) × 3
54:((5 + 2) + 1) × 3
55:(5 + (2 + 1)) × 3
56:(5 × (2 + 3)) - 1
57:5 × (2 + 3) - 1
58:(5 + 1 + 2) × 3
59:((5 + 1) + 2) × 3
60:(5 + (1 + 2)) × 3
61:(5 - 1) × 2 × 3
62:((5 - 1) × 2) × 3
63:(5 - 1) × (2 × 3)
64:(5 - 1) × 3 × 2
65:((5 - 1) × 3) × 2
66:(5 - 1) × (3 × 2)
67:(5 + 3) × (2 + 1)
68:(5 × (3 + 2)) - 1
69:5 × (3 + 2) - 1
70:(5 + 3) × (1 + 2)