Fill in the missing information in the following table of four neutral atoms

Question

Symbol- 37Cl

number of protons- 36 46

number of neutrons- 42

number of electrons- 33

mass number- 77 106

Answer 1

I don't understand

Answer 2

I'm looking for the missing information in the table

symbol-

number of protons-36

number of neutrons-42

number of electrons-

mass number-

Answer 3

The number of protons in 37 Cl is 17. What's confusing is I don't know what the 36 46 means.
The number of neutrons is 37-17 = 20. I don't understand the 42.
The number of electrons is 17.
The mass number is 37. I don't understand the 77 106.