There were 45 runners to start a race. In the first half of the race, 2/3 of them dropped out. In the second half of the race, 4/5
of the remaining runners dropped out. How many runners finished the race?
runners?

What is the difference between regular convex and concave polygons

Find an equation of the line perpendicular to the graph of 28x-7y=9 that passes through the point at (4,1)

Acompany that manufactures and sells guitars made changes in their product range. from the start they had 20 models. then they reduced the number of models to 15. as a result, the company enjoyed a 10% increase in turnover. - how much did the stock level change? in (%)