List of top Mathematics Questions on types of sets asked in JEE Main

Let S be the set of values of λ, for which the system of equations  
6λx – 3y + 3z = 4λ2 ,  
2x + 6ly + 4z = 1, 
3x + 2y + 3λz = l has no solution. Then  12$∑ _{λ ∈ S}$ | λ | 12 ∑ λ ∈ | λ |  is equal to ________ .

The set of all a∈ R for which the equation x|x-1|+|x-2|+a=0 has exactly one real root is

Two sets $A$ and $B$ are as under: $A = \{(a, b) \in R \times R : |a - 5| < 1$ and $|b - 5| < 1\}$; $B = \{(a, b) \in R \times R : 4(a - 6)2 + 9(b - 5)^2 \leq 36\}$. Then