Which term best describes a mixture of sand and marbles?

Asolution contains 180 g of glucose (c6h12o6) and 162 g of water. what is the mole fraction of glucose?

In the millikan oil drop experiment they determined that every drop had a charge which was a while number multiple of -1.60x10^-19. if a drop has a total charge of -9.60x10^-19 then how many excess electrons are contained within the drop?

Ineed to find the answer of this question because i dont understand it