The common factors for 20 is 1,5
25 is 1,5
40 is 1,5
GCF:5
Answer: Third option is correct.
Step-by-step explanation:
Since we have given that
Total watches in an inventory = 1000
Number of shipments sent out = 168, 231, 411
So, Remaining inventory of watches would be :

New receipts = 21, 145 and 11
So, Number of watches on hand becomes :

Hence, Third option is correct.
The difference between two numbers are
and numbers are
and
so the equation is 
How to find the equation and what is the equation ?
equation, statement of equality between two expressions consisting of variables and/or numbers. In essence, equations are questions, and the development of mathematics has been driven by attempts to find answers to those questions in a systematic way.
if the difference of two numbers are 
And one number is
and another is 
So we write the equation with operation of subtraction

Learn more about the equations here :
brainly.com/question/28048736
#SPJ4
Answer:
n+7
Step-by-step explanation:
When we have any unknown quantity, we can call it mostly x,y,z
so, here
Let take an unknown number = n
then
we need to do here " sum of a number and 7 in algebraic form"
so, it becomes
n + 7 (Answer)