Answer:
Replace "is" with =, "less than" with –, and "a number" with n to get 16 = n – 5
Explanation:
Hi, to answer this question we have to analyze the statement given and write an equation: 
Sixteen is five less than a number 
So, the number sixteen (16) is (=) five less (-5) than a number (n). 
We have to subtract 5 to a number (x) and that expression must be equal to 16. 
Mathematically speaking: 
16= n-5 
So, the correct option is: 
Replace "is" with =, "less than" with –, and "a number" with n to get 16 = n – 5 
Feel free to ask for more if needed or if you did not understand something.