RRB Group-D Model Paper 18 with answers for online practice

Given:
One root of the equation is $5-2\sqrt{5}$
Concept:
If one root of the quadratic equation is in this form ( $\mathit{a}+\sqrt{\mathit{b}}$ ) then the other roots must be conjugate ( $\mathit{a}-\sqrt{\mathit{b}}$ ) and vice-versa.
Quadratic equation: ${\mathit{x}}^2$ - (sum of root) + (product of root) = 0
Calculation:
Let α = $5-2\sqrt{5}$ and β = $5+2\sqrt{5}$
sum of root = α + β = $5-2\sqrt{5}+5+2\sqrt{5}$ =10
Product of root = α β = $\left(5-2\sqrt{5}\right)\left(5+2\sqrt{5}\right)$ = 25 - 20 = 5
Now, Quadratic equation = ${\mathit{x}}^2$ - 10x + 5 = 0
Hence, required quadratic equation is ${\mathit{x}}^2$ - 10x + 5 = 0