Shawna does her math homework every night. Last night, Shawna spent 45 minutes solving 15 math problems. Tonight, she needs to solve 10 math problems.
If she does them at the same rate, how many minutes will Shawna spend solving tonight's math problems?
If Shawna spent 45 minutes solving 15 math problems, she spent 45/15=<<45/15=3>>3 minutes solving each math problem
Since she needs to solve 10 math problems tonight, she will spend 10*3=<<10*3=30>>30 minutes solving them. Answer: \boxed{30}.