Catherine studied for 45 minutes for her science test. This was 20 minutes less than she studied for her algebra test. Write and sovle a subtraction equation to find how long she studied for the algebra test.

Lizette is training for a marathon. at 7: 00 she left her house and ran until 8: 30, then she walked until 11: 30. she covered a total distance of 18 miles. her running speed was six miles per hour faster than her walking speed. find her running and walking speeds in miles per hour.