Two math teachers come together and write math problems about fruit vendors. If Teacher A can write 50 problems in 60 minutes and Teacher B can write 50 problems in 80 minutes, how long would it take them to write 50 problems if they worked together?

The bottom of ignacio's desktop is 74.5cm from the floor. ignacios sits in his adjustable chair, and the tops of his legs are 49.3cm from the floor. each clockwise rotation of the knob on the chair raises ignacio's legs by 4.8cm. write an inequality to determine the number of clockwise rotations, r, ignacio could make with the knob without his legs touching the desk.