in the B+ tree order of internal node and order of leaf node are different

order of internal node is maximum no of childrens

order of leaf node is maximum no of key value pair in the leaf

in the question it is given that

B+ tree with fan-out (the number of pointers per node) equal to 3

so from this we can easily conclude that the order of internal node is 3

and order of leaf node is 2 ( just think about it why it is 2 ?? you will get the answer )

for internal node

since order = 3, so we can have 2 key elements in a node this is not problem but when we have 3 key then we have to split them

for leaf node

since order = 2, so we can have 2 key elements in a node with no problem but when we have 3 key then we have to split them

( just think about it why it is 2 ??

it is because given fan-out (the number of pointers per node) equal to 3

one pointer point to next leaf and two pointer point to the record means there are maximum two record pointer

and order of leaf node is maximum number of key value pair

so it is 2