##### find minimum no. of nodes , and minimum number of levels in B+ trees.

no. of keys are 250 ,order is 7 (i.e maximum PTR per node B+ tree)

find minimum no. of nodes

find no. of levels

and also minimum input output cost

no. of keys are 250 ,order is 7 (i.e maximum PTR per node B+ tree)

find minimum no. of nodes

find no. of levels

and also minimum input output cost

min. no of nodes =ceil(250/6) = 42 // when every node is full

min. no. of levels= 250 *[7

^{n}-1]/(7-1) = 3