Answer:
the mechanical advantage is 10
Step-by-step explanation:
The computation of the mechanical advantage is as follows:
Mechanical advantage is 
= Load ÷ Effort
where, 
The Loan is equivalent to the weight i.e. 500 lb
And, the effort is equivalent to the force applied i.e. 50lb
So, the mechanical advantage is 
= 500 ÷ 50
= 10
Hence, the mechanical advantage is 10