Respuesta :
To find unit rate for all 24 problems.
12 problems completed in 1 hour = 12 in 60 minutes
Last 12 problems in 3 hours = 12 in 180 minutes
Total 24 in (180+60= 240) minutes
Time taken to solve one problem = 240/24 = 10 minutes.
This means Deandra on an average took 10 minutes to solve each problem.
12 problems completed in 1 hour = 12 in 60 minutes
Last 12 problems in 3 hours = 12 in 180 minutes
Total 24 in (180+60= 240) minutes
Time taken to solve one problem = 240/24 = 10 minutes.
This means Deandra on an average took 10 minutes to solve each problem.
If you divide 12 by 3 the correct answer should be 4 problems per hour.