I need help from someone smart! I have this chemistry problem and just cant get it (#2)

[Emily Violet]

Hi My name is Sarah I really need some help 

The potassium salt of benzoic acid, potassium benzoate, can be created by the reaction of potassium permanganate and toluene (C7H8(l)). By products of the reaction are manganese (IV) oxide, potassium hydroxide and water. If the yield of potassium benzoate cannot realistically be expected to be more than 68%, what is the minimum number of grams of toluene needed to achieve this yield while producing 10.0 g of potassium benzoate?

Im just lost as of what to do I dont know if I got it but here is the formula. It just dosint look right to me 

KMn04+C7H8=Mno2+KOH+H2O