Try another version of this question Get help: Box 1: Enter your answer as a number (like 5, -3, 2.2172) or as a calculation (like 5/3, 2^3, 5+4)
Betty can mow a lawn in 60 minutes. Melissa can mow the same lawn in 90 minutes. How long does it take for both Betty and Melissa to mow the lawn if they are working together?
minutes
Enter DNE for Does Not Exist, oo for Infinity `36`