Marcy played the piano for 45 minutes. she stopped playing at 4: 15 p. m. at what time did she start playing the piano ?

She started at 4:10. If she ended at 4:15 she started 45 minutes ago. I converted 4:15 into 4.15 and took away .45 I ended with 3.7 but in time there are only 60 minutes in an hour. So I added an hour and took away 60 minutes. This all resulted in 4.10, which you finally turn back into 4:10. (hope this helped)

Well 4:15 minus 15 minutes is 4:00. So subtract 15 from 45 to make sure that you remember. 45-15=30. 4:00 minus 30 minutes is 3:30. So the answer is 3:30