Allen practiced the guitar 1 1/4 hours today he practiced 2/3 of an hour before lunch. how long did he practice after lunch

The answer is 35.

Step-by-step explanation:

1 and 1/4 hours total.  2/3 was performed before lunch. You need to find how long he practiced after lunch. So first you need to find a common denominator (CD) because the denominators aren't the same. When you find the CD for 1 and 1/4 you need to make it an improper fraction (IF) because it's a mixed number. When you do that you get 5 multiplied by 3 and then 4 multiplied by 3 doing this is helping you find the CD of 5/4 which happens to equal 15/12. Next you do the same for 2/3 but this time you multiply 2 by 4 and then 3 by 4 and in this case 2/3 now equals 8/12. Now you can work with finding how much Allen performed after lunch. To find this you need to subtract 15/12-8/12 to find how long he performed after lunch when you do that you get 7/12 hours which is equal to 35 minutes.