3 is your lucky number
For question one, You need to multiply 10 by 3. To get this you can divide 30 by 10, this gives you the number you need to multiply 10 by, in this case its 3.
The next two questions are not able to be answered because I need the amount of oil or flour to determine how much to use for 30 cupcakes.
But, if you have 1 cup of oil for 10 servings, and you want 30 servings, like before, multiply by 3.
Same for flour, it doesnt matter how much of it you need, just multiply by 3 from the amount you use for 10 servings.
If your confused on 4, 5 and 6. Just remember, 3 is the lucky number.