Someone please help me

Name the most appropriate metric unit for each measurement like the mass of cow

Jude is making cement for a driveway. the instructions show the amount of each ingredient to make 1 batch of cement. complete each statement to adjust the ingredients for each new situation if jude uses these instructions.

During the election for class president, 40% of the students voted for kellen, and 60% of the students voted for robbie. 500 students voted in total. how many more students voted for robbie than for kellen? answer with work : )