I know the answer is 4 but how do I show it to the following word problem:
Dan has a rectangular graph 10 inches wide and 8 inches high that he needs to paste into a report for his class. He'll use a photocopy machine repeatedly to reduce the size of his graph. With each reduction, the width and the height will each be reduced to 80% of what they were. What is the minimum number of reductions using the photocopier that will allow the graph to fit in a space 3.5 inches high?