32 bits for indexing outer page table.
So no of outer page entry=2^32.
Now among 64 bit virtual address 32 bit for outer page table index,16 bit for inner page table index..and rest 16 bit offset.
So page size=frame size=2^16 .
So among 64 bit physical address (64-16)=48 bit for frame no/indexing frame.
Now outer page table will contain address of inner page table i.e particular frame address.
So each outer page table entry size=48 bit.
So,Outer page table size=2^32*48=24GB.(No Option Matching)