during a certain four year period the consumer price index desecrated by only 5% but during the next four year period it decreased by 10% which of these conditions must have existed during the second four year period

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 : )