A positive number, when increased by 10 equal 200 times its reciprocal . What is the number?

Let the positive number be N.
According to the question,
N + 10 = 200/N
⇒ N² + 10N = 200
⇒ N² + 10N - 200 = 0
⇒ ( N - 10) ( N + 20) = 0
&ythere4; N = 10 and N = -20
But N ≠ -20, since N is a positive number.
So, the required number is 10.