Q.

Let A and B be two finite sets with m and n elements respectively. The total number of subsets of the set A is 56 more than the total number of subsets of B. Then the distance of the point P(m, n) from the point Q(−2,−3) is                [2024]

1 6  
2 8  
3 10  
4 4  

Ans.

(3)

Total number of subsets of set A=2m

Total number of subsets of set B=2n

According to question, 2m-2n=56

2n(2m-n-1)=23×7

2n=23 and 2m-n=8=23

n=3 and m-n=3m=3+n=3+3=6

m=6 and n=3

Now, distance between the points P(6, 3) and Q(-2, -3) is given by PQ=(6+2)2+(3+3)2=64+36=10 units