2014 · Q7
A positive number, when increased by 10, equals 200 times its reciprocal. What is that number?
Elementary MathematicsAlgebra
- A100
- B10
- C20
- D200
Explanation
x + 10 = 200/x gives x^2 + 10x - 200 = 0, i.e. (x+20)(x-10) = 0; the positive root is 10.