1). Call the number 'N'. The difference between the number and ten is (N-10). Twice the difference between the number and ten is 2(N-10). That's all the question asks for. There's no way to find what number 'N' is.
2). Call the mystery number 'Q'. Twice the number is 2Q. If 5 is subtracted from twice the number, you have (2Q - 5). But it tells us that the result would be 11 . So write (2Q - 5) = 7 and solve that simple equation to find what 'Q' is.
3). Call the mystery number 'Z'. The quotient of the number and 4 is Z/4. If you add 5 to the quotient of the number and 4, you have (Z/4 + 5). It tells us that the result would be 10. So write (Z/4 + 5) = 10 and solve that simple equation to find what 'Z' is.
4). I'm sorry. I don't know what this question is asking for.
