Answer:
The number of seashells he have in his collection all together is 140.
Step-by-step explanation:
Given:
Stanley has a collection of seashells. He found 35% of his collection on Florida beaches.
Stanley has 49 seashells from Florida.
Now, to find the number of seashells of his collection altogether.
Let the number of seashells all together be 
Percentage of seashells found on Florida beaches = 35%.
Number of seashells found on Florida beaches = 49.
Now, to get the number of seashells altogether we put an equation:

⇒ 
⇒ 
⇒ 
Dividing both sides by 0.35 we get:
⇒ 
Therefore, the number of seashells he have in his collection all together is 140.
Attached solution with detailed work.
Answer:
By doing 3 divided by 5, you will get 3/5 of trail mix per person.
Step-by-step explanation:
A factor of 20 but not a multiple of 5 would probably be 4