If X is 20% less then Y, then find the value of Y - X/Y and X/X - Y :

Answer: Option A

20% = $$\frac{1}{5}$$ = $$\frac{4}{5}$$
X  :   Y
4   :   5
Let X = 4a
    Y = 5a
Hence,
⇔ $$\frac{Y-X}{Y}$$
= $$\frac{5a-4a}{5a}$$
= $$\frac{a}{5a}$$
= $$\frac{1}{5}$$
⇔ $$\frac{X}{X-Y}$$
= $$\frac{4a}{4a-5a}$$
= $$\frac{4a}{-a}$$
= - 4
Hence required answer = $$\frac{1}{5}$$, - 4