Question

Several arithmetic problems are shown below.

3+4+5 = 3.4
7+8+9= 3.8
12+13 + 14 = 3.13
20+21+22= 3.21
15+ 16+ 17 = 3.16
Write a conjecture based on a pattern that you notice.
… how do you write a conjecture based on the pattern

Answer 1

40+41+42=3.41

Explanation:

3+4+5=3.4 means three numbers, then dot, then the 2d number (4);

7+8+9=3.8 means three numbers, then dot, then the 2d number (8);

20+21+22=3.21 means three numbers, then dot, then the 2d number (21);

15+16+17=3.16 means three numbers, then dot, then the 2d number (16);

for example, 40+41+42=3.41 - according to the rule described above.