It took Mary Lou 5/6 hour to write a report for English class. It took Heather 9/10 as much time to write her report as it took Mary Lou. Who took longer?
So, Mary Lou took\(\frac{5}{6}\) of an hour, that is \(\frac{5}{6}*60 mins=50 mins\)
Heather took \(\frac{9}{10}\) as much time as Mary Lou, so she took \(\frac{9}{10}\) of 50 minutes, that is \(\frac{9}{10}*50=45\)
45 minutes is less than 50, so Heather was faster and Mary Lou was slower and took longer!