How did you figure out values such as sqrt 50 for option D, could you please explain further?
I think this question is pretty relevant. The key is to select numbers that quickly eliminate incorrect options. All you need is one good example to rapidly narrow down your choices -
A. \(|x| + |y| = 10\) => x=10 & y=0
B. \(|x| \gt |y|\) => x=10 & y=0
C. \(|x| \gt |y| + 10\) => x & y can take max value of 10, because in that case other variable would be 0. And if we have, y=0.01, then x=10.01 as per this equation, which is not possible, hence this is incorrect.
D. \(|x| = |y|\) => x=sqrt(50) & y=sqrt(50)
E. \(|x| - |y| = 5\) => This could seem a bit tricky to eliminate directly but one way here could be to square this => x^2 + y^2 - 2|x||y| = 25 => 2|x||y| = 75. So there does exist some value of x & y satisfying this equation.
IMO: C
If you can't figure out direct ways, figure out smart ways to quickly walk through options.