Problem: How to work out heart rate zones
Calculate your maximum heartbeats per minute by subtracting your current age in years from 220 if you are a man, and from 226 if you are a woman.
For example, if you are a 30-year old man, subtract 30 from 220. Your maximum heartbeats per minute is 190.

Answer: You can also visit a doctor or health-care provider to have them calculate your maximum heart rate using different tests. Methods of testing may include a stress test or exercise tolerance test on a treadmill.

Problem: How to use the undo and redo commands
Shake your iphone or ipad.
Doing so opens a dialog box asking if you want to " undo " the action you just performed.
Tap undo.

Answer: The last action you performed, such as typing, cutting, copying, or pasting, will be undone. Alternatively, on ipad, tap 123 in the lower-left part of the keyboard, then tap undo Shake your iphone or ipad after an " undo " action.

Problem: How to deal with being allergic to cats
Create a cat-free zone.
Your bedroom is your castle. Defend it from allergens at all costs! If you can keep the cat out of your bedroom, you create an (mostly! ) allergen-free zone at night.
Answer: That gives your system a chance to recover overnight. If you're looking for a moat to defend your bedroom, consider a hepa filter.