She can buy 9 pineapples. I don't know why anyone would need that many pineapples
It is an open series circuit and this is why:
its obvious its a series circuit because all the symbols are in a straight rectangle.
its an open circuit because an open circuit has something that doesn't allow the electrons to flow all the way. and the thing blocking the electrons it the switch which is open, (off).
Hope this helped!! sorry its late!!
25 moles of C3H8 will be produced from 75 moles of CO2.
<h3>Mole calculation</h3>
To find the value of moles of a product from the number of moles of a reactant, it is necessary to observe the stoichiometric ratio between them:

Analyzing the reaction, it is possible to see that the stoichiometric ratio is 1:3, so we can perform the following expression:
C3H8 CO2


So, 25 moles of C3H8 will be produced from 75 moles of CO2.
Learn, more about mole calculation in: brainly.com/question/2845237